HOW TO USE THIS COMPETENCY BASED LEARNING MATERIAL
Welcome to the module in Reviewing, Designing and Interpreting Blue Print for
Tank. This module contains training materials and activities for you to complete.
The unit of competency " Construct Aquaculture Facilities_" contains knowledge, skills and
attitudes required for Aquaculture. It is one of the specialized modules at National Certificate
level (NCII).
You are required to go through a series of learning activities in order to complete each
learning outcome of the module. In each learning outcome are Information Sheets and
Resources Sheets (Reference Materials for further reading to help you better understand the
required activities). Follow these activities on your own and answer the self-check at the end of
each learning outcome. You may remove a blank answer sheet at the end of each module (or
get one from your facilitator/trainer) to write your answers for each self-check. If you have
questions, don’t hesitate to ask your facilitator for assistance.
Recognition of Prior Learning (RPL)
You may already have some or most of the knowledge and skills covered in this learner's
guide because you have:
• been working for some time
• already completed training in this area.
If you can demonstrate to your trainer that you are competent in a particular skill or skills,
talk to him/her about having them formally recognized so you don't have to do the same training
again. If you have a qualification or Certificate of Competency from previous trainings, show it to
your trainer. If the skills you acquired are still current and relevant to the unit/s of competency
they may become part of the evidence you can present for RPL. If you are not sure about the
currency of your skills, discuss this with your trainer.
At the end of this module is a Learner’s Diary. Use this diary to record important dates, jobs
undertaken and other workplace events that will assist you in providing further details to your
trainer or assessor. A Record of Achievement is also provided for your trainer to complete
once you complete the module.
This module was prepared to help you achieve the required competency, in Constructing
aquaculture facilities. This will be the source of information for you to acquire knowledge and
skills in this particular trade independently and at your own pace, with minimum supervision or
help from your instructor.
Talk to your trainer and agree on how you will both organize the Training of this unit.
Read through the module carefully. It is divided into sections, which cover all the skills,
and knowledge you need to successfully complete this module.
Work through all the information and complete the activities in each section. Read
information sheets and complete the self-check. Suggested references are included to
supplement the materials provided in this module.
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Most probably your trainer will also be your supervisor or manager. He/she is there to
support you and show you the correct way to do things.
Your trainer will tell you about the important things you need to consider when you are
completing activities and it is important that you listen and take notes.
You will be given plenty of opportunity to ask questions and practice on the job. Make
sure you practice your new skills during regular work shifts. This way you will improve
both your speed and memory and also your confidence.
Talk to more experience workmates and ask for their guidance.
Use the self-check questions at the end of each section to test your own progress.
When you are ready, ask your trainer to watch you perform the activities outlined in this
module.
As you work through the activities, ask for written feedback on your progress. Your
trainer keeps feedback/ pre-assessment reports for this reason. When you have
successfully completed each element, ask your trainer to mark on the reports that you
are ready for assessment.
When you have completed this module (or several modules), and feel confident that you
have had sufficient practice, your trainer will arrange an appointment with registered
assessor to assess you. The results of your assessment will be recorded in your
competency Achievement Record.
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SECTOR : AGRI-FISHERY
QUALIFICATION : AQUACULTURE NC II
UNIT OF COMPETENCY : Construct Aquaculture Facilities
MODULE : Reviewing, Designing and Interpreting Blue Print for
Tank
INTRODUCTION:
This module covers determining the number, size of compartment and depth of tanks and the
identification of suitable materials to be used for tank. It also deals with the procedures for
preparing the farm lay-out using primarily plot markers to guide the process. This also facilitates
the appropriate decisions as to locate the other farm facilities.
Tanks and ponds primarily differ in size and materials of construction. Tanks are typically
smaller than ponds and can be constructed using a variety of materials. Nonetheless despite
the difference in scale, the other critical ingredients for their design and construction based on
the level of capitalization and production remain the primary determinants.
LEARNING OUTCOMES:
At the end of this module you will be able to:
1. Determine number, size of compartment, depth of tank, based on the area
available and the species for culture.
2. Identify materials to be used as to production and capitalization.
3. Plot markers as guide to the lay-out
4. Determine number of farm facilities to be used.
ASSESSMENT CRITERIA:
1. Number and size of compartments are identified
2. Tank depth is determined
3. Materials are listed and identified
4. Budgetary requirement is properly computed
5. Bill of materials for tank
6. Markers are plotted to identified area of construction
7. Importance of markers is explained
8. Number of farm facilities are determined
9. Other farm facilities are planned and laid out
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QUALIFICATION : AQUACULTURE NC II
UNIT OF COMPETENCY
MODULE : Construct Aquaculture Facilities
LEARNING OUTCOME #1 : Reviewing, Designing and Interpreting Blue Print for
Tank
: Determine number, size of compartments, depth of
trucks, base on the area available and the species for
culture
ASSESSMENT CRITERIA:
1. Number and size of compartments are identified
2. Tank depth is determined
RESOURCES: Tools and Instrument Supplies and Materials
Equipment and Facilities 1. Camera 1. Lay-out plan
2. Voice recorder 2. Notebook
3. Pen
REFERENCES:
Caldwell, James. 1998. Why Use Aquaculture as an Educational Tool? The Conservation
Fund’s Freshwater Institute. PO Box 1889 Shepherdstown, West Virginia .Conservation Fund
Version 3.0.
Helfrich, Louis A. And George Libey . --.Fish farming in recirculating aquaculture systems (RAS)
Department of Fisheries and Wildlife Sciences Virginia Tech
Masser, Michael P. and John W. Jensen. 1991. SRAC Publication No. 103. Calculating Area
and Volume of Ponds and Tanks. Southern Regional Aquaculture Center. Alabama
Cooperative Extension Service
Rakocy, James E.1989. L-2409 SRAC Publication No. 282.Tank Culture of Tilapia.. Southern
Regional Aquaculture Center.
http://ag.arizona.edu/azaqua/extension/Classroom/Tanks.htm
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•
Learning Outcome #1: Determine number, size of compartments, depth of trucks, base
on the area available and the species for culture
LEARNING ACTIVITIES SPECIAL INSTRUCTIONS
1. Read the following information sheets:
• Information sheet #1-1: “Different • Information sheet #1-1: “Different
tank shapes and sizes” tank shapes and sizes”
• Information sheet # 1-2: “Designs of • Information sheet # 1-2: “Designs
different tank systems” of different tank systems”
• Information sheet # 1-3: “Measuring • Information sheet # 1-3:
tanks” “Measuring tanks”
• Information sheet # 1-4: “Species • Information sheet # 1-4: “Species
selection” selection”
2. Farm visits and observations of functional Job sheet # 1-1: “Farm visits and
tank systems. observation of functional tank
systems
3. Do Self-Check # 1-1
4. Check your answer Self-Check # 1-1
Answer Key # 1-1
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INFORMATION SHEET #1-1
DIFFERENT TANK SHAPES AND SIZES
Fish Culture Tanks
Fish can be grown in tanks of nearly every shape and size. Fish tanks typically are rectangular,
circular, or oval in shape. Circular or oval tanks with central drains are somewhat easier to
clean and circulate water through than rectangular ones. Rectangular tanks are usually built
with or set upon inclined floors to facilitate cleaning and circulation.
Rearing tanks range in size from 500 to 500,000 gallons capacity. The size of the tank depends
on a variety of factors including: stocking rates, species selected, water supply, water quality,
and economic considerations. The tank must be designed to correspond with the capacity of
other components of the system, particularly size of the biofilter and sump so that all parts of
the system are synchronized.
Tanks can be constructed of plastic, concrete, metal, wood, glass, rubber and plastic sheeting,
or any other materials that will hold water, not corrode, and are not toxic to fish. Smooth
surfaces on the inside of the tanks are recommended to prevent skin abrasions and infections
to the fish, and to permit cleaning and sterilization.
Light weight, durable, plastic tanks can be conveniently moved and readily cleaned when
necessary, but they require special support to prevent stretching when filled with water.
Stainless steel also is a good tank material, but can be expensive. Marine-grade plywood tanks
are inexpensive, but leak if not properly sealed and are not as durable as tanks of other
materials. Concrete tanks may be the most economical to build, but they are relatively
permanent and immovable structures once constructed. Non-toxic plastic or rubber liners can
but used over frames made of wood, metal, concrete, or other materials.
Tank Shape
Most tanks can be classified as circular, rectangular, or oval with a dividing wall.
Circular Tanks
Circular tanks are often used, with the water inlet providing a tangential velocity component.
This causes a rotary water tank circulation. Discharge is typically at the center by means of a
stand pipe or bottom drain (Figure 1).
Circular tanks have several advantages. Normally, water velocities are higher in circular tanks,
leading to better conditioned fish. It tends to have a better feed distribution than raceways and
are more self-cleaning.
Advantages
• water velocities are higher (better conditioning of fish)
• better feed distribution (more efficient feeding)
• more self-cleaning (easy removal of waste)
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Disadvantages
• cost of construction may be more expensive depending on the materials used
• construction may be more difficult
Figure 1. Circular Tank
Rectangular Tanks
Rectangular tanks (Figure 2) are widely used because they are easy to construct. However,
circulation in rectangular tanks is characterized by “dead” areas and short circuiting. Local
oxygen depletion can occur, or metabolic products can build-up in “dead” areas, causing fish
stress if not death.
Advantages
• easy to construct
Disadvantages
• fish may crowd in one corner and deplete oxygen in that corner
• circulation is characterized by dead areas resulting to local oxygen depletion
stressing the fish
• tendency to build-up waste products at the bottom due to poor circulation
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Figure 2. Rectangular Tank
Oval Tanks
Oval tanks (Figure 3) are made up of two parallel straight sections separated by a divider. Two
1800 turn end sections connect the ends of the two straight sections, allowing water to circulate
continuously around the oval. Velocity is imparted to the water by forcing the inlet water through
a nozzle and pointing the nozzle in the direction of the circulation. Water velocity can also be
controlled by placing a paddle wheel at some point in one or both straight sections of the tanks.
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Figure 3. Oval Tank
INFORMATION SHEET # 1-2
DESIGNS OF DIFFERENT TANK SYSTEMS
There are a variety of tank designs which are of standard use in aquaculture systems. These
include round tanks, D-ended tanks, and raceways. General descriptions and benefits of each
are listed below.
Round Tanks
Round tanks have the advantage of a naturally self cleaning action. As the water swirls around
the tank, solids are drawn towards the middle, where the outlet is situated. Due to this property,
they are often used in hatcheries, where due to high feed rates, solids loadings (waste feed and
faeces) can be very high and also in recirculation systems, to remove the solids as soon as
possible, before they break down. Round tanks can be constructed of almost any material, the
most common being fiberglass (for tanks 8m diameter and under), steel (lined or unlined) and
concrete or concrete block. Other materials can be used as long as it is strong enough to hold
the water without distortion and is non-corrosive, non-abrasive and non-toxic. Round tanks
generally have a slope of about 1:50 (2%) on the bottom towards the center outlet to increase
solids removal efficiency. Other qualities of round tanks include: a good mixing of the water,
resulting in easy oxygenation; and less contact of the fish with the tank sides and bottom, due to
a higher ratio of tank volume : tank wall and bottom. Many species prefer the consistent current
of a round tank to other systems. The disadvantages of round tanks include poor use of land
area and difficulties in management (fish removal, screen cleaning), especially in tanks with a
diameter larger than 5 meters.
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Raceways
Raceway is a general term given to a straight sided artificial channel in which fish are held.
Generally these have a high water turnover rate, occuring in less than one hour. The
advantages of raceways are that they can be easily built in series, with the water flowing from
one to the other and that they are easy to empty of fish by using a simple crowding screen. To
be self cleaning, raceways must be operated at high flow rates and/or high stocking densities,
where the movement of the fish keep the faeces and uneaten feed from settling. Disadvantages
of raceways are brought about primarily by poor mixing, and include the gradual deterioration of
the water quality along the length of the raceway (whereas round tanks tend to be more even).
Difficulty in efficient distribution of additional oxygen throughout the raceway can prove to be
another disadvantage. Raceways are usually built with a width to depth ratio of between 2:1
and 4:1, with the length limited either by the amount of fish that can be held in a single holding
unit or the deterioration of water quality. The even nature of raceways means that they are
somewhat flexible, allowing screens to be placed anywhere along the length of the raceway,
thus dividing a single unit into 2 or more smaller units. Modifications to the designs include
rounded bottoms to concentrate solids for ease of cleaning by vacuuming - especially where
small fish are involved. Aeration along the length of the raceway may also be included, which
serves to maintain more even oxygen concentrations along the length of the raceway, and also
concentrates settled solids into specific areas to make cleaning easier. Other modifications
include the addition of barriers in the raceway to create a swirling motion in the water where
waste concentrates. Raceways are advantageous in that they can be constructed with basic
building materials such as bricks, blocks or poured concrete and require little specialized labour.
Raceways vs Round Tanks
Water exchange is a very important factor to consider when designing an aquaculture system.
The water turnover rate will determine how quickly and completely it is filtered and/or sterilized
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and, what the ammonia and oxygen levels will be. Sedimentation and/or self cleaning
characteristics are also very important.
In a raceway tank, an almost complete water exchange can be achieved with one equal
volume of water. As the water flows into the system, it pushes the old water ahead of it. Self
cleaning may be accomplished with high stocking rates and low water levels.
In a round tank, a lot of mixing occurs between the
new and the old water before it reaches the drain. In a
typical 1000L tank, when 1000L of new water is added
to the tank, the water exchange will only be about
60%, meaning the tank will now hold 600L of new
water. To achieve a 98% water exchange it will take
over 9 times the amount of water already in the tank!
Self cleaning is typically very good in tanks less than
30 feet in diameter even with flat bottoms partially due
to centripetal force.
Round tanks may be less expensive but not utilize
space as well as raceways. The decision gets even
more complicated when you consider deep round
tanks (silos), cross flow raceways, "D" ended tanks,
and other styles.
D-ended tanks
D-ended tanks are a type of holding unit which are very economical in terms of space. These
tanks can be constructed from most materials, including fiberglass and concrete. They enables
a lower tank turnover time, without compromising velocity rates and self cleaning abilities. Inlet
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pipes and aeration / oxygenation devices are positioned to create the desired water velocity
rate. Useful in situations where space and make up water are limited.
Source: http://ag.arizona.edu/azaqua/extension/Classroom/Tanks.htm
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INFORMATION SHEET # 1-3
MEASURING TANKS
Most tanks used for holding and transporting fish are rectangular. Rectangular volume is
calculated by the formula:
Volume = length x width x depth
When measuring a tank, take inside measurements of length and width and the depth at the
appropriate water level. If a standpipe or other type of overflow drain is present then the height
to the overflow should be the depth measurement. If the bottom of the tank is sloped toward the
drain an average depth measurement should be used. To get average depth of the tank take
three measurements: at
the shallow end, in the middle, and at the overflow. Add these depths together and divide the
total by 3.
Fig. 1-1. Figuring volume of a rectangular tank
For example, a rectangular tank, without a sloping bottom (see Figure 1-1, above), has a
measured inside width of 36 inches, a length of 72 inches and a depth at the standpipe overflow
of 24 inches. The calculated volume is 62,208 cubic inches (36 x 72x 24).
In many cases it will be necessary to convert cubic inches (in3) to either cubic feet (ft3) or
gallons. Table 4 gives simple ways to make these conversions. Cubic inches are converted to
cubic feet by multiplying by 0.000579 (or by dividing by 1728). Cubic inches are converted to
gallons by multiplying by 0.00433 (or by dividing by 231). A volume of 62,208 in 3 is the same
as 36 ft3 (62,208 x 0.000579 or 62,208 + 1728) and 269 gallons (62,208 x 0.00433 or 62,208 ÷
231).
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Circular tank volume (Figure 1-2) is determined by the formula:
Volume = 3.14 x radius2 x depth
The radius is measured as 1/2 the inside diameter of the tank. The radius is squared or
multiplied by itself.
For example, a circular tank with an inside diameter of 72 inches and a standpipe depth of 24
inches has a volume of 97,667 cubic inches (3.14 x 36x36x 24).
Using Table 4 the volume can be converted into cubic feet (97,666.56 ÷ 1728 = 56.52) or
gallons (97,666.56 ÷ 231= 422.8).
Figure 1-2. Circular tank volume.
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Masser, Michael P. and John W. Jensen. 1991. SRAC Publication No. 103. Calculating Area
and Volume of Ponds and Tanks. Southern Regional Aquaculture CenterAlabama Cooperative
Extension Service
Available area for the tank site
Water is heavy. Situate the tank on solid ground. If the tank is on a hillside, excavate enough
room for the entire tank on solid ground. Ferro cement will last for many years, stable ground is
important. Excavated soil is not suitable for the tank site.
Enough room for work is also important. Where earth may fall, make the site larger.
Contamination entangled in the structure is a problem during construction.
Volume Calculation
π r2 h = volume (where π = 3.14, r = radius, h = height)
Mark the Tank
After the ground is level, smooth, and tamped, put a stake in the center. Make a circle in the
dirt, use a light rope for the radius. Mark this circumference with white flour or other white
material. The white circle will become a good tank.
The pictures which accompany the beginning of this guide are from an eight foot diameter
wading pond.
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INFORMATION SHEET # 1-4
SPECIES SELECTION
Selecting fish species for culturing are dependents on the following factors:
Environmental condition. The fish should be able to cope with the existing condition in the
tank environment and the place as well (see case of Tilapia nilotica in Florida). Although this
can be controlled, it is more favorable if the species are already acquainted the local/regional
condition to avoid additional expenses on purchasing life support systems gadgets to maintain
them.
Breed of fish. The fish must be of quality breed and has the characteristics to adjust in tank
culture condition. This is also related to rate of survival and mortality of fish in terms of disease
and pest resistant and immunity. Economically, the produce of the particular species
commands a fair price in the market due to familiarity of the species(see discussion on why
tilapia).
Feed availability and other sustenance. The feeds and other needs of the fish must be easily
accessible and they can be found in the local market.
Rules and regulations. There could be an existing local ordinances which allow and disallow
the culture of some fish species. This may due to environmental reason, taking into account the
biodiversity pool of their place and protecting the area for possible ecological disturbances.
The case of Tilapia nilotica in Florida
The most appropriate species of tilapia for tank culture in the U.S. are Tilapia nilotica, T. aurea,
Floridared tilapia, Taiwan red tilapia, and hybrids between these species or strains. The choice
of a species for culture depends mainly on availability, legal status, growth rate and cold
tolerance. Many states prohibit the culture of certain species. Unfortunately, T. nilotica,which
has the highest growth rate under tropical conditions, is frequently restricted. Florida red tilapia
grow nearly as fast as T. nilotica and have an attractive reddish-orange appearance. T. aurea
grow at the slowest rate under tropical conditions, but this species has the greatest cold
tolerance and may have the highest growth rate in temperate regions at temperatures below
optimum.
Why use Tilapia?
There are many fish to choose from when selecting a species for aquaculture production. The
aquaculture principles are the same no matter what species is selected. You could produce
sportfish fingerlings for recreation, foodfish fingerlings that could be sold to producers for
growout, or growout your own foodfish. More familiar, native species that could be selected for
production include: catfish, walleye, perch, hybrid striped bass, striped bass, and trout. The
major advantages of using these familiar, native species would be: 1) ready availability of seed,
fry or fingerlings; 2) familiarity of consumers with the product; and 3) no permits would be
required for handling these fish. The use of a native species would be more consistent for a
program that emphasizes environmental conservation. You might consider setting up an
aquarium or taking a field trip to a local hatchery as a way of exposing students to the culture of
native species.
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JOB SHEET # 1-1
Title Farm visits and observation of functional tank
Purpose systems
Equipment, Tools and Materials To apply learnings and skills in determining number
Precautions and size of tanks
Notebook, camera, pen
Follow workplace procedure.
Procedures:
1. Arrange a visit in aquaculture facilities.
2. Make observation of the functional tank systems of the aquafarm.
3. Take note of your findings, including important details and data.
4. Based from your experience and gained skills during the visit, create your own
functional tank systems for the area. Include the following information:
determine number and size of compartments
depth of trucks,
available areas
species for culture
5. Submit this to the facilitator. Be ready for discussing your output with facilitator
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SELF CHECK # 1-1
1. Differentiate circular tanks from rectangular tanks in terms of advantages and
disadvantages:
Tanks Advantages Disadvantages
Circular Tanks
Rectangular Tanks
2. What are the formulas in getting the rectangular and circular tanks volume?
3. What are the factors in selecting fish species for culturing?
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ANSWER KEY # 1-1
1. Differentiate circular tanks from rectangular tanks in terms of advantages and
disadvantages:
Tanks Advantages Disadvantages
Circular Tanks
• water velocities are • cost of construction
higher (better may be more
conditioning of fish) expensive
• better feed distribution depending on the
(more efficient materials used
feeding) • construction may be
• more self-cleaning more difficult
(easy removal of
waste)
Rectangular Tanks • easy to construct • fish may crowd in
one corner and
deplete oxygen in
that corner
• circulation is
characterized by
dead areas
resulting to local
oxygen depletion
stressing the fish
• tendency to build-
up waste products
at the bottom due to
poor circulation
2. What are the formulas in getting the rectangular and circular tanks volume?
Rectangular tank volume
Volume = length x width x depth
Circular tank volume
Volume = 3.14 x radius2 x depth
3. What are the factors in selecting fish species for culturing?
• Environmental condition.
• Breed of fish
• Feed availability and other sustenance
• Rules and regulations.
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QUALIFICATION : AQUACULTURE NC II
UNIT OF COMPETENCY
MODULE : Construct Aquaculture Facilities
LEARNING OUTCOME #2 : Reviewing, Designing and Interpreting Blue Print for
Tank
: Identify materials to be used as to production and
capitalization
ASSESSMENT CRITERIA:
1. Materials are listed and identified
2. Budgetary requirement is properly computed
3. Bill of materials for tank
RESOURCES:
Equipment and Facilities Tools and Instruments Supplies and Materials
1. List of materials
2. List of dealers
3. Price list
REFERENCES:
----------.FS No. 41/03: Recirculating aquaculture tank production systems-an overview of critical
considerations. Primary Industries and Resources SA.
http://www.ferrocement.com/tankBook/intro.en.html
http://www.ferrocement.com/tankBook/ch1.en.html
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Learning Outcome #2 : Identify materials to be used as to production and capitalization
LEARNING ACTIVITIES SPECIAL INSTRUCTIONS
1. Read Information sheets on the following: • Information sheet #2-1: “Tank culture
system: identifying materials needed
• Information sheet #2-1: “Tank culture in the plan”
system: identifying materials needed in
the plan” • Information sheet # 2-2: “Materials
needed in constructing a tank”
• Information sheet # 2-2: “Materials
needed in constructing a tank” • Information sheet # 2-3: “Site
preparation and calculations”
• Information sheet # 2-3: “Site
preparation and calculations”
2. Activity #2-1 Conduct a simple market • Activity Sheet #2-1: “ Market survey
survey of dealers and canvas availability and canvassing of availability and
and prices of materials for tank system prices of materials for tank system”
3. Do Self-Check # 2-1 • Self - Check # 2-1
4. Check your answer • Answer Key # 2-1
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INFORMATION SHEET #2-1
TANK CULTURE SYSTEM: IDENTIFYING MATERIALS NEEDED IN THE PLAN
Tanks are smaller than pond and are constructed using variety of suitable materials. They are
also constructed in various shapes. However, whatever is the size or shape of tank the
following characteristics of an ideal culture tanks should be satisfied
The difference between tanks and ponds is primarily of size and materials of construction.
Ponds are larger and of earthen construction, whereas tanks are smaller and constructed of
concrete, fiberglass, or other suitable materials. The variety of tanks used for culture of
organisms is endless, ranging from home aquariums to oval tanks 100 feet long along the major
axis.
The ideal culture tank has at least the following characteristics:
1. It is smooth on the interior.
2. It is self-cleaning
3. Provide water of high quality
4. It is durable and has sufficient mechanical strength
5. It is easily cleaned and/or sterilized
6. The interior surface is non-toxic
7. It is as inexpensive as possible
8. It does not corrode
Materials for Tank Construction
1. Concrete – it is widely used for larger culture tanks. It is durable, low cost material, and it
can be formed easily into the desired shape. However, most concrete tanks are permanent
installation.
Advantages
• widely used for larger culture tanks
• durable and low cost
• can be formed into the desired shape
Disadvantages
permanent installations
high in calcium carbonate and new installation often increase water
pH – flushing or washing before use is required to reduce pH
2. Wood – it is one of the most inexpensive materials but it requires coating to prevent rotting.
Plywood
Advantages
• less expensive
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Disadvantages
• require coating inside and outside to prevent rotting
3. Plastic or Fiberglass – it is light, strong and is inert to freshwater and to salt water. It can
also be moulded into desired shapes, although most fiberglass tanks are circular. Fiberglass
is strongest in tension loading.
a. Fiberglass – widely use plastic material for tank construction
• light, strong and reasonably priced
• inert to freshwater and marine water
• can be easily molded
b. Vinyl Flexible Plastic widely used for swimming pool lines
• inexpensive and flexible
• zero permeability
• smooth and easy to clean
However, vinyl are easily damaged/punctured and cut, so contact with sharp or pointed
surfaces must be avoided.
c. Polyethylene – similar in properties to vinyl but does not elongate
that much
• widely used for making impermeable liner for low cost, rigid structures
• available in rolls up to 6m wide and 75m long
• can be purchased in many thickness based on user’s conditions
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 24
INFORMATION SHEET # 2-2
MATERIALS NEEDED IN CONSTRUCTING A TANK
Supports and Vertical Reinforcing Bar
Support
Build the girder on the ground or in place. Support is required for a girder built in place.
The support can be a wood scaffold, or, angle iron which spans the distance. Finished
girders built on the ground are lifted into position by a crane. Girders built on the ground
or on wood scaffold need 1/2 inch (1.27 cm) concrete support blocks for the steel, this is
a custom size made on site before the girder is built.
If angle iron is the chosen method, and the length requires welding, be sure the resulting
length of steel angle iron is straight. 1 1/2 to 2 inch (3.8 to 5 cm) angle iron is sufficient. It
should be 1/8 to 3/16 inches thick (30 to 50 mm). Lift the angle iron into place, use care
to avoid bending it. loosely attach the ends. Allow for 1/2 inch (1.25 cm) of plaster under
the angle iron. Support the angle iron with a 2x4 post so that the span is divided in half.
Use a stretched string to make sure the angle iron span is flat and straight. Measure the
2x4 support carefully before cutting. Burn a hole in the bottom of the angle iron and drive
a nail through the hole and into the 2x4 post. Secure the ends of the angle iron.
Arc Welding Reinforcing Bar
Arc welding reinforcing bar adds another dimension to ferro cement strength. Use low
hydrogen welding rod. Weld one side only to flat steel surfaces. A weld on both sides of
a round shape causes the flat shape to bend around the circular shape: when the welds
cool and shrink. Weld rapidly. Minimize cutting into reinforcing bar with arc blow, add
dimension with the weld. Clean and paint welds, especially on larger projects which take
longer to complete.
Vertical Reinforcing Bars
Start at the center. Mark angle iron every 9 to 10 inches (23 to 25 cm). Use # 4 bar. Start
with one for the middle. Bend a right angle. Use a torch or make a jig to cold bend as
tight as possible. Make it four feet (1.2 m) vertical and 6 3/4 inches horizontal (17 cm).
This horizontal size is very minimal and assumes such a small size is chosen so it will fit
on top of 2x8 or 2x10 framing material. Weld the vertical in place at the center. Put one
weld on the horizontal portion of the angle iron, and another weld on the vertical. Cut two
15 foot (4.5m) lengths of reinforcing bar. Use straight ones. Tie togeather with two foot
overlap (60 cm). Temporarily tie the 26 foot (8 m) to the center vertical at a designed
height or one that looks about right. Pull the ends down to position and temporarily tie.
Make two more verticals to divide the span into quarters. Make them longer than
necessary for arc adjustments. View the curve and make final adjustments. Tie light lines
to the center vertical to keep the girder armature stable. Fill in verticals.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 25
Horizontal Reinforcing Bars and Start Welded Wire
Put a layer of welded wire on the outside of the girder (the side away from the bottom
bend). Position the bottom of the welded wire 1/4 to 3/8 inch (6 to 9 mm) above the
bottom of the angle iron. Put a horizontal bar on the outside 18 to 20 inches up (45 to 50
cm). Follow this with layer of welded wire inside the verticals. Stagger the welded wire so
the horizontals and verticals are 1 1/2 inches apart (3.8 cm). The girder has four layers of
welded wire with an optimum pattern of 3.8 cm squares. Now put a horizontal bar on the
inside at 9 to 10 inches (23 to 26 cm) up , then put another inside horizontal 18 to 20
inches (45 to 50 cm) above the first. Fill in on the outside to create a 9 to 10 inch (23 to
26 cm) staggered grid of reinforcing bar. Put a #3 bar at the bottom of the outside welded
wire. Put another arc at the top on the other side of the verticals from the first.
Adjust grid space at the arc line according to workmanship, the grid does not need to be
perfect squares at the arc line. Workmanship at the top curve is determined by what the
girder is for and what connects to it.
Bottom Angle of Girder
If this is a freespan top loaded girder (no walls underneath) the bottom horizontal should
be a a larger "L" than the dimension used above, or, a "T" rather than an "L" (built on a
scaffold, rather than with angle iron). If this is a free span bottom loaded girder, the top
should be a "T". In these cases, all vertical to horizontal bends can be a larger radius
because they need not fit into angle iron.
The Steel Armature: Wall Steel
Floor to Wall Key
Straighten the upright reinforcing bars which come out of the key. Make 2 foot overlaps
on horizontal circumference reinforcing bars. Length helps the overlap area keep a nice
circumference curve: Too short, and the ends pop outward. Tie a horizontal
circumference of #4 bar two to three inches above the key, as level as possible. Patch in
a piece to complete the circumference. #4 bar is mentioned because it aids circular
perfection, #3 bar is strong enough. Readjust The verticals. Put another circumference of
#3 bar 10 to 12 inches above the first. Make sure everthing is level and plumb.
Inside Layer of Welded wire (7' Tall)
Cut a piece of welded wire long enough to make an inside circumference plus plenty of
overlap (2'). Roll this wire up backwards, very loosely, to relieve wire strain from the
factory roll, then unroll and re-roll back to original direction. Stand the wire up inside the
tank. Unroll about halfway and attach the middle at the upper circumference bar. Use the
virticals of the welded wire so this layer can slide up and down a little. If the key steel is
plumb and the welded wire is level, the wall will be plumb. Center cut the bottom
horizontal wire every three feet. Slightly bend the tails toward the key, so they won't
protrude when the plaster is applied. Tie welded wire to lowest bar and below. Don't tie
too tight, don't stress wire, keep it smooth and the tank will stay a good cylinder.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 26
Vertical Reinforcing Steel
Cut enough 20 foot bars into thirds for vertical spacing of 24 inches or less. #3 bar is
sufficient for tank strength, but #4 bar is better at supporting heavy, wet plaster. The
verticals need not be perfectly spaced, nor do they all need to be tied to the verticals that
come up from the floor. The verticals are placed inside the first two horizontal rings of
bar. Tie them inside the horizontal bars. Check for verticality with a level. Adjust those
that need it. Put a loose tie to the welded wire at about 5 feet.
Circumference Bars and Outer Welded Wire Layer
Space circumference wraps at 12 to 15 inches. First tie a bar in the middle, then work
both ways, leave the last two feet loose until the next bar is ready to tie at the overlap.
Bend the ends of the overlap slightly if they tend to protrude outward. Skip up two and
put on a higher circumference, and then work down. When the top circumference is
complete, unroll welded wire around the outside. Stagger the squares to make 3x3 inch
squares. The outside and inside diameters of the tank wall are different enough that the
staggered square pattern will gradually become equal. Cut the wire before this happens,
overlap two feet and restart the stagger pattern of 3x3 inches. Cut the lowest horizontal
wire every three feet, the next wire up may also need cutting every five or six feet. Tie
the outside and inside layers togeather in a pattern similar to tightening lug bolts on a tire
(one side then the other). Don't tie the upper 6-9 inches too much because tails from roof
reinforcing steel will extend 12-15 inches down into the wall.
The Steel Armature: Outer Mesh
Expanded Metal Lath (Thin Gauge)
Begin with the wall. Tie or hog ring the sheets of lath to the wall. This is not the final tie,
securely in place is enough for now. Standard U.S. metal lath sheets are about 8 feet
(2.44 m). Since the walls are slightly less than 7 feet (2.1 m), the metal lath will curve up
into the first foot of interior ceiling. Trim the sheets to make overlaps of 3/4 inch (2 cm).
Finish walls and then do the ceiling. Use the 2x4 supports to help hold the lath in place.
When the interior lath is complete, put a layer of chicken wire on the outside roof, extend
it down the wall about one foot (30 cm) below the curve.
The Hatch
Locate the hatch above the inlet pipe to facilitate maintenance of plumbing parts and
observe water flow. Make the opening large enough to remove the ladder. If the ladder
base is 28 inches (70 cm) make the finished hole size 30 (76 cm) inches and the rough
opening 31 inches (79 cm). To accomplish the example size, start with a 32 1/2 inch
circle of #3 bar wired to the roof (83 cm). Trim steel and bend welded wire in a
convienient way. Plan for at least a 1 1/2 inch (4 cm) cement curb around the finished
hole.
A ferro cement hatch can be either hinged and locked with a hasp, or locked down with
two hasps. If hinged, use a large gate hinge. Tie extra welded wire and steel to the hinge
where it attaches to the roof and hatch, do the same thing to the locking hasp. The hatch
begins with a circle of #3 bar which is about 4 inches (10 cm) larger than the completed
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 27
roof hole. Then fabricate a small version of the tank roof with hinge and hasp attached.
The dome shape of the hatch will accomodate the plaster curb around the roof hole. Tie
hinge and second locking hasp part to the roof. Reinforce these areas with welded wire
patches and reinforcing bar scraps. A ferro cement hatch is heavy, the hinge and locking
hasp should be fairly large. The hatch is plastered after the tank has cured for a few
days.
Finish Tie the Steel Armature
The outer layer of fine wire may be: welded hardware cloth with 1/2 inch (1.25cm)
squares, thin expanded metal lath, or two layers of chicken wire (with the wires of the
second layer bisecting the holes of the first layer). The outer wall layer only needs to
reach the beginning of the roof curve, the roof chicken wire is sufficient to hold the wet
plaster in place at the curve. If the outer layers of fine wire are loose, there will be sags
and bulges of heavy plaster.
There are two ways to secure the fine steel so it won't bulge. One is with hog rings. A
pneumatic hog ring gun or hog ring pliers are required. These may be obtained from an
upholstery supply store. Tie the underlying welded wire, where it is loose, with loops that
go all the way through the tank. If hog rings are not available, stitch the seems of metal
lath. One person passes the wire through and another passes it back. Tighten every third
or fourth stitch. After all the seems are tight, stitch around and around the tank. Work
upward to the wall curve. Space each pass around the tank eight to ten inches above the
last (20 to 25 cm). Although this method takes the most time, the result is excellent when
the stitching is good and tight.
Stitching also works well for the roof, reduce the spacing to six inches (15 cm) or less.
Another procedure is to tie a third layer of welded wire tightly up against the inside ceiling
lath. The six inch (15 cm) squares of welded wire hold the metal lath up very well. Finish
plaster the ceiling to cover this layer well.
Plumbing
Plumb the outlet and cleanout pipes. Be sure the cleanout pipe (4") is slightly below the top of
finished concrete. Place plastic pipe on the shady side of the tank. Use schedule 80 sunlight
resistant even on the shady side. If pipe exits on the sun side, use brass. It is a good idea to
glue 1" squares of pipe material on the outside of the 4" plastic pipe so it won't spin inside the
concrete in future years. Clamp these pieces for several hours while the glue cures. Braze
some bumps on brass pipe for the same reason.
If the plastic drain pipe must be placed on the sunny side of the tank, drape a piece of metal
lath on top of it and plaster the exposed pipe. This will add many years before the sunlight
makes the plastic drain pipe brittle.
A third way to make the outlet is a plastic sleeve which is large enough for the pipe to slide
through. For example: 2'' pipe slides into 2 1/2" pipe. Using the example, a 2" pipe with washer
and compression fittings on inside and outside tank surfaces can be easily replaced when
necessary.
Floor Cement
For a true ferro cement floor: support the floor steel with 1" dobe blocks rather than 1 1/2"
blocks, then add a top layer of chicken wire. Inspect for wires that may protrude above the
finished concrete surface. Adjust or replace them now. The ferro cement floor will be about 2 to
2 1/2" thick.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 28
The cement to sand ratio is 2.7 to 3 sand for one cement. Don't use extra water. If a finger mark
in the mix settles very slightly, it is a good mix. Mix the cement well. Use a plaster mixer,
wheelbarrow, or mezcla. Retrowel shrink cracks. Use a stiff broom and water on shrink cracks
when the material becomes too hard to work with a trowel. Keep tank floor wet always.
When the concrete is hard, flood with water to top of wall key. Place black plastic over water
and drape over the key to the ground. Hold plastic down with dirt. Tie it to vertical rebars. Wait
three or four days to start the wall steel. Then keep the floor wet still. Twenty eight days is a
perfect concrete cure. Ninety percent cure is quite a bit less time, depending on tempurature.
Use the same basic procedure to begin a ferro cement tank inside an old tank or silo.
Bottom Angle of Girder
Cut enough one foot (30 cm) strips to span the girder. Strips overlap one foot (30 cm). Bend
these pieces into "U" shape. Make the small dimension one inch (2.54 cm). Bend the pieces
over a one half inch board (1.27 cm). Work the pieces until they are well shaped.
Make enough 18 inch (46 cm) strip to span the girder. Bend these pieces so that the smaller
dimension is 1/2 inch back from the ends of the reinforcing bar stubs. These pieces go outside
and under the "L". Cut and bend a 12 inch (30 cm) strip which fits the same way on the inside
corner of the "L". Cut and set aside another 12 inch strip of welded wire which spans the girder.
When all the pieces are worked into finished shapes, put the "U" shaped strip on the #4
horizontal reinforcing bar (bottom of "L").
Horizontal Reinforcing Bar (Span Direction)
Put three #4 reinforcing bars on top and two or three underneath. Wire or weld in place. Burn
two or three small holes in both angle iron surfaces, between each vertical reinforcing bar.
Clean off slag.
Finish Welded Wire and Metal Lath
Put the 18 inch strip on the outside corner and the 12 inch strip along the inside corner. When
these layers are secured in place, Bend the last 12 inch (30 cm) strip into a "U" that fits over the
other wire and steel on the short part of the "L". Make a a nicely squared "U". Place another
layer of welded wire on each vertical surface of the girder. Tie the girder securely. The steel
should feel tight.
Metal Lath
Start metal lath at the top of the vertical surfaces. The outside piece extends down and under
the "L". This piece goes all the way around the bottom of the last "U" It ends one inch (2.54 cm)
in at the top of that "U". The top inside corner and the horizontal surface do not need metal lath.
The plaster will pack better without it. The inside metal lath surface extends from the top of the
girder to just above the inside corner. Leave the inside corner open for good plaster packing..
Stich or hog ring the metal lath in place. The girder is ready to plaster.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 29
Plaster
Start plaster in the center and work towards both ends. Mix and apply plaster as described in
the tank section.
Expanded Metal Lath (Thin Gauge)
Begin with the wall. Tie or hog ring the sheets of lath to the wall. This is not the final tie,
securely in place is enough for now. Standard U.S. metal lath sheets are about 8 feet (2.44 m).
Since the walls are slightly less than 7 feet (2.1 m), the metal lath will curve up into the first foot
of interior ceiling. Trim the sheets to make overlaps of 3/4 inch (2 cm). Finish walls and then do
the ceiling. Use the 2x4 supports to help hold the lath in place. When the interior lath is
complete, put a layer of chicken wire on the outside roof, extend it down the wall about one foot
(30 cm) below the curve.
The Hatch
Locate the hatch above the inlet pipe to facilitate maintenance of plumbing parts and observe
water flow. Make the opening large enough to remove the ladder. If the ladder base is 28 inches
(70 cm) make the finished hole size 30 (76 cm) inches and the rough opening 31 inches (79
cm). To accomplish the example size, start with a 32 1/2 inch circle of #3 bar wired to the roof
(83 cm). Trim steel and bend welded wire in a convienient way. Plan for at least a 1 1/2 inch (4
cm) cement curb around the finished hole.
A ferro cement hatch can be either hinged and locked with a hasp, or locked down with two
hasps. If hinged, use a large gate hinge. Tie extra welded wire and steel to the hinge where it
attaches to the roof and hatch, do the same thing to the locking hasp. The hatch begins with a
circle of #3 bar which is about 4 inches (10 cm) larger than the completed roof hole. Then
fabricate a small version of the tank roof with hinge and hasp attached. The dome shape of the
hatch will accomodate the plaster curb around the roof hole. Tie hinge and second locking hasp
part to the roof. Reinforce these areas with welded wire patches and reinforcing bar scraps. A
ferro cement hatch is heavy, the hinge and locking hasp should be fairly large. The hatch is
plastered after the tank has cured for a few days.
Finish Tie the Steel Armature
The outer layer of fine wire may be: welded hardware cloth with 1/2 inch (1.25cm) squares, thin
expanded metal lath, or two layers of chicken wire (with the wires of the second layer bisecting
the holes of the first layer). The outer wall layer only needs to reach the beginning of the roof
curve, the roof chicken wire is sufficient to hold the wet plaster in place at the curve. If the outer
layers of fine wire are loose, there will be sags and bulges of heavy plaster.
There are two ways to secure the fine steel so it won't bulge. One is with hog rings. A
pneumatic hog ring gun or hog ring pliers are required. These may be obtained from an
upholstery supply store. Tie the underlying welded wire, where it is loose, with loops that go all
the way through the tank. If hog rings are not available, stitch the seems of metal lath. One
person passes the wire through and another passes it back. Tighten every third or fourth stitch.
After all the seems are tight, stitch around and around the tank. Work upward to the wall curve.
Space each pass around the tank eight to ten inches above the last (20 to 25 cm). Although this
method takes the most time, the result is excellent when the stitching is good and tight.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 30
Stitching also works well for the roof, reduce the spacing to six inches (15 cm) or less. Another
procedure is to tie a third layer of welded wire tightly up against the inside ceiling lath. The six
inch (15 cm) squares of welded wire hold the metal lath up very well. Finish plaster the ceiling to
cover this layer well.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 31
INFORMATION SHEET # 2-3
SITE PREPARATION AND CALCULATIONS
This portion discusses factors to be consider in preparing the place where you will set-up the
tank. Although this is more of establishing a water tank, but the information may also be found
useful for fish tanks. Likewise, how to make some basic calculations are also presented here.
In this case we have a 60 cubic meters tank.
Site location and preparation
Water is heavy. Be sure to locate the tank on solid ground. Cut enough room for the entire tank
to sit on solid ground if the tank is going to be on a hillside. Excavated soil is not good for a tank
site because it will settle over time. Ferrocement water tanks last for decades and stable ground
is important.
Enough room for working is also an important consideration, especially on the uphill side. Make
the site large enough so dirt and rocks don’t fall into the steel armature. Contamination
entangled in the structure is a problem to avoid during construction. The area made up of
excavated fill is a good place for the access road to terminate and to store materials. If this is a
large tank and the excavated material is a mountain of dirt poised to cause damage below
during a flood year, then it should be placed on a cut bench cut of its own and be compacted for
stability and safety.
Volume Calculations:
πr2h = volume (where π = 3.14, r = radius, and h = height)
The following example is for a tank of sixty cubic meters; height is 2.13 meters.
πr2(2.13) = 60 cubic meters (sixty thousand liters)
r2 = 60 cubic meters ÷ (2.13 x 3.14) = 8.971 m2
r = radius = 3 meters
2r = diameter = d = 6 meters
Strength Calculations:
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 32
Sixty cubic meters is used in this example because many ferrocement tanks have been built of
this size and there have been no problems, even after twenty-five to thirty years. Tanks of this
age in the 200 to 400 cubic meter class have likewise shown no problems. Two hundred cubic
meters is somewhat more difficult to build and 400 cubic meters is the beginning of a heavier
construction project size.
Convert the depth into pressure, measured in grams per square centimeter and calculate the
circumference in centimeters.
πd = 3.14 x 6 meters = circumference = 1884 centimeters.
The pressure on a square centimeter (kg/cm2) = the depth of 2.13 meters = 0.213 kilograms per
square centimeter.
This means that there is 0.213 kilograms of outward pressure on a one centimeter square at the
bottom of the tank wall. Since the wall is 1884 centimeters around, the total outward force on
the bottom centimeter of wall is 0.213 x 1884 = 401 kilograms.
The next step is to determine the strength of the wall as it resists this outward pressure. The
concrete plaster is only considered as waterproofing for the steel in this calculation. All the
strength is assumed to be in the steel. Add up the horizontal strands of welded wire and the
bars which encircle the tank. Count the welded wire and the reinforcing bars separately since
they are different strengths of steel. Reinforcing steel is 3515 kilograms of tensile strength per
square centimeter and the welded wire is 6328kg/cm2.
There are five horizontal wires and two reinforcing bars in the bottom thirty centimeters of this
sixty cubic meter tank. Ignore the welded wire bent to come up and out of the floor until further
along the discussion. Standard welded wire is ten gauge wire on 7.5 centimeter squares. Ten
gauge wire is 0.356 cm diameter.
πr2 = 0.1 square centimeters of steel times five wires = 0.5 square centimeters. Multiply this by
6328 kilograms per square centimeter = 3164 kilograms of tensile strength in the bottom 30
centimeters of wall. Divide by 30 to compute the welded wire strength in an average centimeter
of wall. 3164 ÷ 30 = 105 kilograms of horizontal welded wire tensile strength per average
vertical centimeter of wall. The same calculation is done for two horizontal wraps of #4 bar (1.27
centimeters).
πr2 multiplied by 2 multiplied by 3515 kilograms of tensile strength per square centimeter =
7030 kilograms of tensile strength in the reinforcing bar, in the bottom 30 cm of wall. Divide by
30 to find the average strength in a centimeter of wall. 7030 ÷ 30 = 234.
The total wall steel strength is 234 + 105 kilograms = 339 kilograms of tensile strength in the
steel. There is an additional #4 bar in the floor-to-wall key which brings the steel strength figure
to 456 kilograms.
The final step in comparing steel tensile strength to water force is to draw a circle and quarter it
as pictured below.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 33
ACTIVITY SHEET # 2-1
Title: Market survey and canvassing of availability and
Purpose: prices of materials for tank system
Equipment, Tools and Materials To apply the knowledge gain in canvassing for
Precautions materials for tank system
Pen, notebook, list of materials
Ensure that you obtained permit from school for
this activity
Procedure:
1. Based on the example plan, make a listing of the materials needed for the construction,
including estimate size and quantity of materials for delivery.
2. Go the local market, and make a canvass of the listed materials.
3. Try to analyze the information you gathered.
4. Make a report out of this activity. Attached all the data you collected. Be prepare for
possible assessment of the facilitator.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 34
SELF-CHECK # 2-1
Modified true or false. Write whether the statement is true or false. Underline the word or
phrase which make it false.
_____ 1. An ideal culture tank is smooth on the interior.
_____ 2. Concrete tanks is widely used for larger culture tanks. It is durable, low
_____ cost material, and it can be formed easily into the desired shape.
3. Tanks made of wood it is one of the most expensive materials but it
_____
_____ requires coating to prevent rotting
_____ 4. Fiberglass widely use plastic material for tank construction
5. Vinyl Flexible Plastic widely used for swimming pool lines
6. Polyethylene similar in properties to fiberglass but does not elongate
that much
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 35
ANSWER KEY # 2-1
Modified true or false. Write whether the statement is true or false. Underline the word or
phrase which make it false.
True 1. An ideal culture tank is smooth on the interior.
True 2. Concrete tanks is widely used for larger culture tanks. It is durable,
False low cost material, and it can be formed easily into the desired shape.
3. Tanks made of wood it is one of the most expensive materials but it
True
True requires coating to prevent rotting
False 4. Fiberglass widely use plastic material for tank construction
5. Vinyl Flexible Plastic widely used for swimming pool lines
6. Polyethylene similar in properties to fiberglass but does not elongate
that much
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 36
QUALIFICATION : AQUACULTURE NC II
UNIT OF COMPETENCY : Construct Aquaculture Facilities
MODULE : Reviewing, Designing and Interpreting Blue Print for
LEARNING OUTCOME #3 Tank
: Plot markers as guide to the lay out
ASSESSMENT CRITERIA:
1. Markers are plotted to identified area of construction
2. Importance of markers is explained
RESOURCES: Tools and Instruments Supplies and Materials
Equipment and Facilities
1. marker
2. string
3. lay-out plan
REFERENCES:
Miller. 2004. Chapter 1: Location of structure on site.pdf
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 37
Learning Outcome #3 : Plot markers as guide to the lay out
LEARNING ACTIVITIES SPECIAL INSTRUCTIONS
1. Read Information Sheet # 3-1: “Use of • Information Sheet # 3-1: “Use of markers to
markers to guide the lay-out plan” guide the lay-out plan”
2. Field visit and observations of farm • Farm visit and observations of actual tank
practices of tank construction using construction especially the use of markers
markers to guide the lay-out plan for lay-out
3. Do Self-Check # 3-1 • Self - Check # 3-1
4. Check your answer • Answer Key # 3-1
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 38
INFORMATION SHEET # 3-1
USE OF MARKERS TO GUIDE THE LAY-OUT PLAN
(this information is an extracted portion of the material entitled Miller. 2004. Chapter 1:
Location of structure on site.pdf)
A number of factors affect the location of a structure on a site, as well as the type of building
that may be erected. Once the site is chosen, different methods may be used to create the plan
for building the structure. Required documentation to attain final approval of the building
includes the plot plan, the Certified Plot Plan, and the Certificate of Occupancy.
Basic Conditions
A number of conditions determine what kind of building may be erected, as well as where on
the lot it may be located, including the following:
• Covenants
• Zoning ordinances
• Well location
• Septic system location
• Corner lots
• Nonconforming lots
• Natural grades and contours
Staking Out House Location
With site analysis completed and a specific location chosen, the next step is to locate each
corner and lay out the building lines. Staking a building on a level rectangular lot is simple. On a
sloping, odd-shaped lot, it is more difficult. In both cases, accuracy is important. Following are
two methods of staking out the house
location:
1. Measuring from a known reference line
2. Using a transit-level
1. Staking Out from a Known Reference Line
When a building is to be erected parallel to the property line, the property line is a known,
identifiable line. The property line becomes the reference point and makes a builder’s level
unnecessary. First, ensure that corner markers or monuments (usually granite in the front and
iron pipes or pins in the rear) are in place. If markers are missing, call the surveyor. From the
plot plan (Figure 1-1), find the setback distances.
Caution
Taping is more difficult than it seems to be. The distances to be measured are horizontal, not
sloped distances. If the lot is sloped and you are downhill from the reference marker, use plumb
bobs and hand levels to keep the tape level. On ground that is level lay the tape on the ground,
rather than supporting each end. On sloping lots, pull hard on the tape to remove most of the
sags. In this instance, a steel tape is best.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
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Figure 1-1 Plot plan showing property lines and corner markers, located and identified,
house location, and setback lines.
To stake out, refer to Figure 1-2 and proceed as follows:
1. Prepare 10 or more 3-foot long stakes by drawing diagonals on the flat head to locate the
center, and drive a nail where the lines cross.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
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2. Locate the right rear property marker D. Measure 45 feet-0 inches from D toward the front
granite marker B. This is the rear yard setback distance. Drive a stake. This stake is marked
E1 in Figure 1-2.
3. Locate the left rear property marker. Measure 45 feet-0 inches from D toward the front
granite marker A. This stake is marked E2.
4. Stretch a line tightly across the lot between stakes E1 and E2to locate the rear yard setback
line. Next, the two rear corners of the house must be located. The plan shows the house is
34 feet from the rear yard setback line. From the left stake E2 measure 34 feet-0 inches
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 41
toward the front and drive a stake, F2. From the right stake E1 measure 34 feet-0 inches
toward the front and drive a stake, F1. Consult the plot plan to see how far in the house
corners will be from the left and right property lines.
5. From the left stake F2 measure in 50 feet-0 inches to the right, and drive a stake. This is the
left rear corner of the house. From the right stake F1 measure in 60 feet-0 inches to the left,
and drive a stake. This is the right rear corner of the house. The distance between these
two stakes is the length of the rear of the building. Confirm that this distance, 46 feet-0
inches, agrees with the length given on the plot plan (Figure1-1).
6. Get the depth of the house from the plot plan. From the left rear corner stake measure 26
feet-0 inches toward the front yard, and drive a stake. This is the left front corner of the
house. From the right rear corner stake measure 26 feet-0 inches toward the front yard, and
drive a stake. This is the right front corner of the house. The distance between these two
stakes is the length of the front of the building. Confirm that it agrees with the length shown
on the plot plan (Figure 1-1). If the property lines form a 90-degree angle at the corners, the
left and right sides of the building should be parallel with the left and right property lines. The
front and rear lengths should be parallel with the front and rear property lines.
On a nonrectangular lot, where the corners do not form a 90-degree angle, this method will not
work because the building lines will not be parallel to the property lines. The setback lines
should be staked out, and the corner of the building closest to the property line, but within the
setback, should be located. The building should be staked out from this point, with a dumpy
level or transit level, using the method described in the “Batter Boards and Offset Stake” section
later in this chapter.
2. Laying Out with a Transit Level
There are two types of surveyor’s levels in common use: the automatic optical level (also known
as a dumpy level or builder’s level, as shown in Figure 1-3) and the transit level (Figure 1-4).
The optical level is fixed horizontally and cannot be used to measure angles. The transit level
can be moved horizontally or vertically, and can be used to measure vertical angles, run straight
lines, and determine whether a column, building corner, or any vertical structure is plumb. The
laser level (Figure 1-5), common in commercial construction, is slowly replacing the transit level
in residential construction. To lay out the building using transit level, a reference point, or
benchmark, is needed. The rear right corner marker serves this purpose. To lay out the building
using a transit level, refer to Figure 1-3 and follow these steps:
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
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Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 43
Caution
When setting up the transit over a marker on a slope, put two of the tripod legs on the downhill
side, and the other leg on the uphill side. Locate the top of the tripod as close as possible to the
marker.
1. Level and plumb the transit over marker D. Sight down to the opposite corner marker B.
The rear yard setback is 45 feet-0 inches. Measure 45 feet-0 inches from marker D. Take
one of the previously prepared stakes, align the 45 feet-0 inches mark on the tape
measure with the center of the stake. Release the transit telescope, and lower it until the
crosshairs, the nail in the center of the stake, and the 45 feet-0 inches mark agree. This
is point E.
2. The house is 34 feet from the rear setback line. From point E1 measure 34 feet-0 inches.
While holding the tape 34 feet-0 inches mark at the nail in the center of the stake, raise
the telescope until the crosshairs are exactly on the 34 feet-0 inches tape mark, and
drive the stake. This is point F1.
3. Move the transit to mark F1, level and plumb it, and sight back on marker B. Now turn the
telescope 90 degrees to the right.
4. The distance from the property line (Figure 1-1) to the right side of the building is 60 feet-
0 inches. From mark F1 measure 60 feet-0 inches and drive a stake. Lower the
telescope until the horizontal crosshair is on the 60 feet-0 inches mark on the tape. This
is the first corner of the building, and it is point G.
5. Move the transit to point G, and level and plumb it. Measure 46 feet-0 inches from point
G. This is the length of the building. Now raise the telescope until the horizontal crosshair
coincides with the 46 feet-0 inches mark on the tape. Align the center of the stake with
the 46 feet-0 inches mark on the tape, and drive the stake. Point H has been located and
is the second corner of the building.
6. With the transit still over point G, turn it 90 degrees to the left. Measure 26 feet-0 inches
from point G. Then, lower the telescope until the horizontal crosshair is on the 26 feet-0
inches mark on the tape. Align the nail with the 26 feet-0 inches tape mark, and drive the
stake. Point I is established and is the third corner of the building.
7. Level and plumb the transit over point I , and sight back to point G. Rotate the telescope
90 degrees to the left. From point I measure 46 feet-0 inches. Lower the telescope until
the horizontal crosshair is on the 46 feet-0 inches mark on the tape. Align the center of
the stake with the 46 feet-0 inches mark on the tape, and drive the stake. This, the fourth
and final corner of the building, is point J .
Batter Boards and Offset Stakes
Now that the building corners have been established, building lines must be set up to mark the
boundaries of the building. Batter boards are used to permanently mark the excavation and
foundation lines. The forms for the foundation walls will be set to these building lines. The batter
boards should be installed 4 to 6 feet back from the building corner stakes. Suspend a plumb
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 44
bob over the building corner stakes to exactly locate the lines over the corner stakes. When all
the building lines are in place, ensure that the measurements between the lines agree with the
measurements shown on the blueprints. Measure the two diagonals of the batter board lines to
ensure that the building lines are square. Offset stakes (an alternative to batter boards) are
stakes that are offset several feet away from the corner markers. Set up and level the transit
over one of the corner stakes, which we will call A. Site down the telescope to establish a
reference point called B, and drive a stake. Set the 360-scale at 0. Now rotate the telescope
until the scale indicates a 90-degree turn. Set up the leveling rod the required distance from the
transit, sight down the telescope to establish point C, and drive a stake. Line AC is
perpendicular to line AB, forming a right angle where the lines intersect at point A. Lines
stretched between the pairs of stakes intersect at point A, one of the house corners.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 45
JOB SHEET # 3-1
Title Farm visit and observations of actual tank construction
especially the use of markers for lay-out
Purpose To apply knowledge and enhance skills in using plot
Equipment, Tools and Materials markers as guide in laying-out
Pen, notebook, pencil, tracing paper
Precautions: • Observe workplace procedures
• Observe safety precautionary measures
Procedures:
1. When you visit a farm observe all the activities in tank planning and constructions,
particularly in using markers for lay-out.
2. Make your own lay-out ; use the attached plan as an example.
3. Follow the procedures found in information sheet # 3-1 in making the lay-out.
4. Submit your report and output to your facilitator. Be ready to discuss this.
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 46
SELF-CHECK # 3-1
SEQUENCING. Write the procedure in “Staking Out from a Known Reference Line” in
order
______ Locate the right rear property marker D. Measure 45 feet-0
inches from D toward the front granite marker B. This is the
______ rear yard setback distance. Drive a stake. This stake is
______ marked E1 in Figure 1-2.
______ Stretch a line tightly across the lot between stakes E1 and
______ E2to locate the rear yard setback line.
______
Prepare 10 or more 3-foot long stakes by drawing diagonals
on the flat head to locate the center, and drive a nail where
the lines cross.
Get the depth of the house from the plot plan.
From the left stake F2 measure in 50 feet-0 inches to the
right, and drive a stake.
Locate the left rear property marker. Measure 45 feet-0
inches from D toward the front granite marker A. This stake is
marked E2
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 47
ANSWER KEY # 3-1
SEQUENCING. Write the procedure in “Staking Out from a Known Reference Line” in
order
2 Locate the right rear property marker D. Measure 45 feet-0
inches from D toward the front granite marker B. This is the
rear yard setback distance. Drive a stake. This stake is
marked E1 in Figure 1-2.
4 Stretch a line tightly across the lot between stakes E1 and
E2to locate the rear yard setback line.
1 Prepare 10 or more 3-foot long stakes by drawing diagonals
on the flat head to locate the center, and drive a nail where
the lines cross.
6 Get the depth of the house from the plot plan.
5 From the left stake F2 measure in 50 feet-0 inches to the
right, and drive a stake.
3 Locate the left rear property marker. Measure 45 feet-0
inches from D toward the front granite marker A. This stake is
marked E2
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 48
QUALIFICATION : AQUACULTURE NC II
UNIT OF COMPETENCY : Construct Aquaculture Facilities
MODULE : Reviewing, Designing and Interpreting Blue Print for
LEARNING OUTCOME #4 Tank
: Determine number of farm facilities to be used
ASSESSMENT CRITERIA:
1. Number of farm facilities are determined
2. Other farm facilities are planned and laid out
RESOURCES: Tools and Instruments Supplies and Materials
Equipment and Facilities
1. Lay-out plan
2. tracing paper
3. pencil
4. ruler
REFERENCES:
----------.FS No. 41/03: Recirculating aquaculture tank production systems-an overview of
critical considerations. Primary Industries and Resources SA.
Losordo, Thomas M., Michael P. Masser and James Rakocy.1998. SRAC Publication No. 451:
Recirculating Aquaculture Tank Production Systems. An Overview of Critical Considerations.
Southern Regional Aquaculture Center.
Tankersley, Richard A. and Steven W. Butz.. 1998. Design, construction and evaluation of a
laboratory-scale recirculating aquaculture system for the captive care freshwater mussels. In:
Proceeding of the Conservation Captive Care and Propagation of Freshwater Mussels
Symposium. Ohio Biological Society.
http://ag.arizona.edu/azaqua/extension/Classroom/startup.htm
Code No. Reviewing, Designing and Interpreting Blue Print Date: Developed Date: Revised Page #
for Tank May, 2005 April, 2006 49
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