Start Aquarium

How to Start Your Own Aquarium 

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Thinking of starting an aquarium store? With a little determination, creativity and money you'll be able to make a profit in no time. Here is how to set up your own home business.

EditSteps

1. 
   1
   Start by planning. Research is the key to success. Investigate how you will lay out your store, price your fish, what kind of fish you will sell and which breeders to contact. Or maybe you would like to breed your own fish. Breeding aquarium fish is one of the steps to becoming a skilled aquarist.
2. 
   2
   Gather supplies. Listed in the "Things You'll Need" section below.
3. 
   3
   Begin breeding and stocking your tanks. Before you add expensive tropical fish to your new tanks, you will need to go through the cycling process. This process is to avoid "new tank syndrome." You should cycle your tanks with a few hearty fish.
   • Add easy breeder fish such as guppies and mollies. Once these have a stable population in your tanks, start buying different types of fish. Stock up on food and medications.
     
4. 
   4
   Make sure your tank setups are working. Fish from a breeder might be ill. If you see signs of illness, remove the fish to a hospital tank. Check your fish daily and change the tank water often. Note: Commercialize your fish tanks as much as possible, but maintain happy fish. Healthy tanks attract customers.
5. 
   5
   Keeping healthy fish can be a challenge. Once your tanks are set up and cycled through, you will need to care for the fish. Maintaining healthy fish will include these tasks:
   • Regular aquarium cleanings and water changes
     
   • Regular filter maintenance
   • Regular feedings, using a variety of healthy foods
     
   • Recognizing any odd behaviors in your fish
     
   • Inspecting your equipment
     
   • Many problems start with water quality. The quality of the water can be compromised when the decorations-rocks, gravel, plastic plants-are added. They may contain limestone which will make the water alkaline. You will forever struggle with maintaining the pH balance in your tank. Make sure the decorations you use are clean, appropriate and of a quality material. ^[1]
     
6. 
   6
   Start up your shop. Once you have the amount of fish and tanks that you want, open your store up. Make sure to obtain the right permits before attempting this step. Read up on starting a small business.^[2]

EditTips

• Quarantine fish before putting them in the tanks, when customers realize you have healthy fish they'll want to come back.
• Certain fish eat their fry. It's a good idea to separate the fry from the adults.
• Divide your store by the various types of tanks you will have. (Freshwater Hi Temp/ Low Temp, Saltwater, Brackish water, Goldfish tanks, etc..)
• Know what fish are aggressive and which are not. You don't want to send 3 fish home with a family and the children watch the bigger one eat the other two! (Unless they are feeders)
• Making each tank maintain itself with the right types of fish and other living things will reduce your maintenance workload some but not all. Still it is worth it to let algae eaters to the first line of defense and other cleaning shrimp, snails and fish provide an added layer of self maintenance.
• Know your general plants and their needs (Lights/Fertilizers) and what types of fish do well in similar conditions.
• Know that goldfish are some of the worst fish as far as keeping water clean and that you will likely have to filter their water 2 to 3 times as much as the others.
• Keep the price of your fish low, but high enough to make a profit.
• Don't sacrifice quality when tempted to buy cheap heaters.
• Test Often. Daily. Keep everything in balance as much as possible (According to the normal "Cycle" of a tank). Don't change the pH unless you know what you are doing.

EditWarnings

• Lock up! Get an advanced security system. Small shops are key targets for burglars.
• Be prepared! Setting up a store requires money, time, energy and the necessary permits. "As a new business owner you will need to know your federal tax responsibilities."
• Maintaining fish takes experience! Learn as much as you can before attempting your own business.

Edit

                                                                                                                                                          Things You'll Need

• 20 gallon fish tanks
• heaters
• under gravel filters
• a power siphon for water changes
• a faucet where you can connect the siphon
• gravel
• fake plants
• Water treatments
• a test kit that analyze

Manual for SMALL FISHFARM

Manual for SMALL FISHFARM SMALL FISHFARM, 2003 Introduction: The SMALL FISHFARM enables persons to raise fish for their own consumption. It requires access to a sea, a river or a lake with clean water. Technical background: The SMALL FISHFARM can provide a good supply of fish protein for a limited number of persons, while avoiding adverse effects on the fish and the surrounding waters. The SMALL FISHFARM is constructed for extensive (rather than intensive or semi-intensive) cultivation techniques. The fish are not fed artificially, but live from algae, plankton, weeds and detritus that occur naturally in the water and on the sea floor. This low-impact method results in somewhat slower growth. However, because the fish are less densely populated there is less competition for food and space, which can cause faster growth rates for individual fish. This is useful in selective harvesting. Intensive or semi-intensive techniques raise the fish uniformly faster by adding feed artificially, which also enables denser stocking, but this will negatively affect the well being of the fish. Also, adding feed only increases growth rate to a nominal extent with a system such as this. And if the farm is overfed, the ecological balance can be disturbed and low oxygen conditions will result. Construction: The SMALL FISHFARM is modular, allowing multiple units to be joined together. Three polyethylene pipes are fixed in a triangular arrangement, end to end, using rubber corner fittings. They provide the floats that hold the fish nets. Three thinner pipes erected from the corners meet in the center to provide support for the top net while also adding further rigidity to the construction. All the materials are non-corrosive and non-toxic. If one raises species that feed off the sea floor, the net must be open in the bottom. This is the case with this version of SMALL FISHFARM. The net is somewhat longer than the depth of the water and is weighed down using heavy steel chains woven along the bottom. In order to be able to lift it, when collecting all the fish at once, or to check the net for damage, ropes are attached in different places to the end of the net. These can be pulled up through the ring that is suspended at the center of the construction. The farm is held in place using three anchors marked with buoys. Mussels can be placed along the bottom, where they will feed off the fish droppings thereby keeping the area cleaner. Fish: A large variety of fish can be raised with the SMALL FISHFARM, but some are especially well suited. In addition to one's taste and preferences, the choice must depend on the salinity, temperature and quality of the water. One must also consider the other organisms that inhabit the water, including algae, seaweed, plants, and other fish species. So as to not disturb the trophic system, it is important to use a fish species native to the body of water being considered. Furthermore, some species require maintenance and feeding while others - if the setting is ideal - can be left more or less to themselves. For common carp raised in an extensive culture, successful stocking density is around two fish per square meter of surface area. First stocking size should be a minimum of about 15 cm in length. Although growth rate varies with size, it is fast enough to harvest fish every year as long as they are reproducing successfully. Carp will usually reproduce with one major spawning season per year during spring or summer. The male-female ratio should be about 1:2. Other possible fish species are pike, zander, trout, salmon (these species are mainly carnivorous and will have to be fed), tilapia, catfish, (both of these are very hardy and can live in low oxygen conditions) grouper (marine), milkfish, eel, and many others. Corner fitting The nets are hooked on to the knobs. The chain weighs down the net. Anchor and buoy. Ropes, fixed to the bottom of the net. Fish net, fixed to the construction. Swan mussels (Anodonta Cygnea). Common carp (Cyprinus Carpio). Nets: The drawbacks to cultivating any finfish in nets include the fact that the small mesh size required for reproduction will inhibit good water circulation, it will become covered in algae and subsequently respiring bacteria quite quickly, and the bottom will be covered in fish waste. This will also cause the oxygen levels in the enclosure to become low, which can be unhealthy or even fatal for the fish and other organisms. However, by making sure the area of the farm has lots of plants, and by stocking a few fish that eat the algae on the net, this problem can be avoided. Another possibility is to use a larger mesh size in the main area for better circulation, and either restocking each year, or having a secondary breeding area with a smaller mesh size used only for spawning and rearing the juveniles to a certain size. Extensions: The SMALL FISHFARM can be extended with a small spawning area connected to the main net. The spawning area must provide a shallow, heterogeneous, and protected environment for spawning and for the growth of the larvae and juveniles. In the case of carp, this area must be no more than 30 cm deep and be densely vegetated. The carp will spawn between the plants. The spawning area should have a fine mesh size to prevent the offspring from escaping, however no mesh size is small enough to retain all the eggs and larvae, but this is not a problem because of the abundance of eggs. As an alternative to this method, one can move the reproductively mature fish at the appropriate times to an external enclosure where they can spawn. For more intensive breeding, a feeding automat can be added. This requires access to electricity, which can be difficult. One solution could be installing a solar panel or a windmill, including a battery to store the energy. More SMALL FISHFARM units can be coupled together at the vertices to form hexagonal or rhombic shapes. Maintenance: Many fish species will themselves keep the nets clean from algae and weeds by feeding off them. If they don't, some cleansing will be necessary. Occasionally, the nets should be lifted and checked for holes and other damage. Sick or wounded fish must be removed from the farm. The largest adults should be harvested first. Component list: 3 polyethylene tubes Ø 20 cm, thickness 11 mm, length 4 m 3 polyethylene tubes Ø 9 cm, thickness 5 mm, length 2.33 m corner fittings in rubber 27 bakelite knobs polyethylene foam 12 x 4 m black nylon net, mesh size 2 x 2 cm nylon thread 12 m steel chain 3 anchors, galvanized steel 3 black buoys 11 mm nylon reinforced rope bolts and nuts 15 pc common carp (Cyprinus Carpio) 100 pc swan mussels (Anodonta Cygnea). SMALL FISHFARM, Bremen, Germany 2003 Back to manuals Back to HOME

DETAILED PLANNING FOR FISH FARM CONSTRUCTION

12. DETAILED PLANNING FOR FISH FARM CONSTRUCTION

12.0 Introduction

1. In the previous chapters you learned how to:

• evaluate a potential site for the construction of a freshwater fish farm;
• select the type of pond best adapted to this site and to your needs;
• lay out your fish farm;
• build earthen ponds; and
• construct the various structures required for proper water control and transport.

2. You have selected a good site both from the technical and economical aspects (see Sections 2.2 and 2.3). You have surveyed this site in detail for its topography and its soils. On these bases and according to your requirements, you have laid out your fish farm and prepared a detailed topographical plan of it (see Section 2.6).

The selected site

3. Now has come the time to decide on the following important issues:

(a) When will the construction begin (see Section 12.1).

(b) Who will construct the farm (see Section 12.2).

(c) How will the construction be done (see Section 12.3).

4. These decisions may lead to further activities, all of which are looked into in this chapter:

(a) Some more detailed plans and drawings may have to be prepared (see Section 12.4).

(b) A series of specifications for the contractor may have to be prepared (see Section 12.5).

(c) A detailed schedule of activities may have to be drawn up (see Section 12.6).

5. Finally, and in all cases, you will wish to know in advance how much the construction of the fish farm will cost (see Section 12.8). 

12.1 When to build the fish farm

1. Before deciding at which time of the year you should build your fish farm, you should ask these questions:

(a) When is the site easily accessible?

(b) When is the soil relatively dry, soft and easily workable?

(c) Will there be water available to fill the pond shortly after building it?

(d) Does it need to be prepared for stocking with fish at a particular time?

(e) Will there be labour, machinery and materials available at that time?

(f) Should I consider building the farm in stages, over several seasons?

2. Accessibility to the site and workable conditions are particularly important if you plan to use machinery for the earthwork. Remember that for materials and supplies such as sand, cement, gravel, wood and pipes, access to the site by vehicles may also be required. It is best to fill the pond with water shortly after construction to avoid the growth of weeds.

3. Under extreme conditions, select the season for construction using the following guidelines;

• swampy conditions: toward the end of the dry season;
• heavy clay soils: toward the end of the rains;
• hard dry ground: end of rainy season.

4. When building a barrage pond, it is best to select the period when the flow of the stream to be dammed is minimal.

12.2 Who will construct the fish farm?

1. There are three possibilities:

• either you construct the farm entirely yourself; or
• you pay a small, local contractor to do it; or
• you do it partly yourself and partly under contract.

2. You should consider constructing all or part of the fish farm yourself, for example when:

• the fish farm to be built is rather small, less than 1 ha, and you can rely on some technical assistance from a specialized extension service;
• there is no qualified contractor available locally, and you have some of the required experience;
• the interested contractors quote prices much higher than your own estimate; check the latter carefully and question the contractors before taking a final decision.

3. If you decide to construct a larger farm yourself, before starting its construction you should:

• decide whether you are going to construct it with or without mechanical means (see Section 12.3);
• prepare the technical specifications for the earthwork and the structures (see Section 12.5);
• prepare a schedule of activities (see Section 12.6);
• plan for the necessary inputs such as labour, tools, supplies/ materials and equipment by working out how much you will need, when you will need these inputs and for how long.

4. If you decide to employ a contractor to do part or all of the construction work, it is simplest to discuss a direct contract with a known contractor and to agree with him on an all-inclusive price for the job. This contractor should not only have the required technical qualifications, but should also have reliable financial credentials.

5. In this last case, you do not have to decide for yourself the best way in which to construct the fish farm according to your plans. This should be done by the contractor. But first, you will have to prepare plans and drawings (see Section 12.4) and specifications for the contract (see Section 12.5). The contractor will base the price of the contract on these plans, drawings and specifications. Compare this price with your own estimate (see Section 12.8) and accept it only if they do not differ too much.

12.3 Constructing the fish farm

1. If you have decided to construct your fish farm yourself, you have two choices of ways to proceed:

• either using manual labour only; or
• using machinery in part and using manual labour in part.

2. The choice largely depends upon the size of the farm to be built and on the availability of machinery. Very small farms up to 1000 m² are usually built using manual labour only. It is also important to have the farm constructed within a reasonable time to bring it into production and reduce the time before earnings are made on your investment.

3. For manual construction you will need simple equipment such as picks, hoes, shovels and wheelbarrows. It can be done by yourself and your family, assisted by some friends if necessary. You can also contract someone to dig the pond manually for a fixed price based on the earthwork. The size of individual ponds generally does not exceed 400 m2 . From the volume of earthwork required, you can estimate how long it will take you to build each pond and, if necessary, how much it would cost you to subcontract its construction (see Section 12.8).
4. Mechanical construction is done with earth-moving machines such as bulldozers and wheel loaders (see Section 4.8). Compaction equipment can also be used. This construction method is much faster and not necessarily more expensive than using manual labour only, but it requires the selected site to be accessible to the machinery and to have adequate soil conditions, It also requires skilled operators. The amount of earthwork should be large enough to justify the costs of transporting equipment to the site. One way of reducing these costs would be to join your neighbours and build several fish farms in the same area, using the same machinery.

5. Normally, you would hire the services of a contractor who owns the necessary equipment. This is usually done either with a price determined by the nature and amount of work to be done or for a weekly, daily or hourly rate. While the latter could be cheaper, you should make sure that the operator is skilled, and be careful if there is a risk of the machinery breaking down or getting stuck during construction. Before discussing the contract, it is best to estimate yourself the volume of earthwork to be done and, from this, the machinery time needed (see Section 12.7). You can do similar calculations for other types of construction work, such as site preparation and dike compaction. Remember that it will always be necessary to use manual labour as well, particularly for finishing the construction.

6. A mixed method is often the most advantageous way to construct medium-size fish farms. This only involves the use of earth-moving equipment, for example an ox-drawn scoop or scraper or a small bulldozer, as discussed in Chapter 4, to speed up the main earth movements. All other types of work are done manually.

12.4 Making detailed plans and drawings

1. At the beginning of this manual (see Section 2.6), you learned how to prepare a topographical plan showing the site elevations and the proposed layout of the fish farm, including all its structures.

2. If the fish farm to be constructed is rather small (less than 5 000 m²) you will not usually need to prepare more detailed plans. It is usually sufficient to mark the main dike boundaries and estimate the volumes of earth required. You will only need to use detailed calculations and markings if the ground is very irregular (see Sections 6.4 to 6.8). As distances are not great, the planning of earth movements is not so important.

3. The most useful additions to the existing topographical plan are the following:

• elevations of the tops of the dikes;
• elevations of the pond bottoms;
• elevations of the feeder and drainage canals;
• characteristics of the dikes (side slope, length, thickness);
• characteristics of the canals (side slope, bottom width);
• characteristics of the roads (elevations, width);
• positions of the other structures such as main water intake, pond inlets/outlets, division boxes on canals, spillways, etc.

General layout for a small fish farm

4. It may also be useful to prepare detailed drawings of the various structures as a basis for estimating their individual cost (see Section 12.8) and for their construction. Elevations should be clearly indicated to avoid any mistakes later.

5. If the fish farm to be constructed is larger (greater than 5 000 m²), it is advisable to prepare more detailed work plans to be closely followed during construction. For each fish pond prepare a topographical work plan in the following way:

(a) Survey the site area in more detail, either by radiation or using a square grid as discussed in Sections 8.1 and 11.4, Topography, 16. This survey is best done after partial clearing of the vegetation (see Sections 5.2 to 5.5), and it should provide you with accurate information on the positions and the levels of the pond site area. At this stage you will have pegged out the pond area.

(b) Start drawing the topographical work plan of the pond area, including all surveyed points.

(c) Determine the best excavation depth to balance cut and fill volumes according to the type of pond (see Sections 6.4 to 6.8).

(d) Make sure that these calculations tie in with the required feeder and drainage canal levels, and that local soil conditions such as areas of rock, permeable soil, sources of clay, etc. are taken into account.

(e) Try to minimize the distances you move earth within the pond, particularly if you plan to build the pond by hand. As an approximate guide, on flat ground you should aim to transport the earth no more than about one quarter of the pond's width and on steeper slopes, no more than two-thirds of the pond's width.

(f) Make sure that access roads or tracks, feeder canals and drains are laid out to service the site efficiently and well.

Note: in some cases, particularly for large sites with many ponds, it may be necessary to move earth from one area of the site to another. Allow for the extra earth volumes taken away or brought into the pond. Check that the earth volumes balance out over the whole site.

(g) Determine the key elevations of the pond.

(h) Complete the topographical work plan of the pond by entering the following information on it:

• the elevations of the top of the dikes;
• the positions and elevations of the inlet and outlet;
• the positions and elevations of any other structure to be built in the pond area;
• the characteristics of the dikes.

6. It is also better to prepare cross-section profiles of the site and the ponds in two perpendicular directions, especially if the site is sloping and if the ponds are to be constructed at different elevations. Indicate on them the key elevations of the ponds and other structures.

7. Add to the existing topographical plan of the fish farm all information relating to the feeder/drainage canals, road system, service buildings, etc., which do not appear on the work plans.

8. Prepare detailed drawings of the various structures, indicating clearly their key elevations and giving a reference number to each kind of structure.

Typical structures for a larger fish farm
Cross-section  feeder canal	Cross-section of a feeder canal with double inlet

Cross-section   pond inlet NOTES: Elevation measurements are in metres; all other measurements are in centimetres

Cross-section of a pond outlet with monk

General layout for a larger fish farm of 16 ponds of 0.25 ha or 4 ha total

Typical cross-section for a larger fish farm

12.5 Making specifications for construction contracts

1. Preparing the specifications for the construction of a larger fish farm can be a very complicated task, and this should be carried out by a qualified technician or engineer. However, if your fish farm is small (less than 5 000 m²), you may prefer to prepare the specifications yourself for its construction under contract, preferably with some assistance from your extension agent.

2. Make a detailed list of the non-technical specifications, under the following headings:

• general description of the site and work to be done, including number and size of ponds, canals and structures;
• description of contractor's responsibilities for the constructions until completion, delivery and acceptance;
• description of supervisory, testing and acceptance conditions;
• description of payment schedule according to work progress;
• time limits for delivery or completion, and possibilities for extension (for reasons beyond contractor's control) and penalties (for late delivery and loss of production/ and interest).

3. List the technical specifications clearly and in detail, referring to available topographical plans and detailed drawings (see Section 12.4). These specifications should deal separately with the earthwork and the structures as follows:

(a) Earthwork specifications:

• site clearing, including total removal of stumps and roots, handling and placing of cleared vegetation;
• removal of topsoil, including details of area, thickness, storage;
• construction of dikes, including the origin and quality of the soil and its characteristics,
• compaction, covering maximum thickness of layers, soil moisture content, type of equipment to be used.

(b) Structure specifications, listing type and quality of materials to be used in each case, such as:

• reinforced concrete, including mix type, slump test limits, reinforcement quality, curing process, forms;
• wood, listing details of species, treatment, relative humidity, storage conditions;
• bricks or concrete blocks, noting quality, finish, type, weight, storage conditions-,
• pipes, listing type, material, storage, handling, laying;
• mortar and plaster mixes, additives, water, etc.;
• paints, specifying number of coats, type.

4. To be able to give a price quotation for the construction contract, the contractor will require all the above specifications together with topographical plans and detailed drawings.

12.6 Making a schedule of activities

1. If you have decided to construct the fish farm yourself, you should prepare a realistic schedule of activities to help you plan for the required inputs.

2. Before starting construction work, in most cases it is necessary to have a preparatory phase in which you will:

stake out the position of the ponds, dikes, canals, etc.; clear the vegetation; remove the surface soil and store it; establish temporary bench-marks ; assemble the construction materials required on the site; stake out in detail the dikes, canals, pond bottom, etc.; dig temporary drains for carrying away excess seepage or runoff; dig protection canals (see Section 11.5).

3. The temporary bench-marks (TBMs) that you establish allow you to determine and check by levelling the elevations of the dikes, canals and other structures (see Section 8.1, Topography, 16). The main points to consider are that:

• the number of TBMs required increases with the size of the farm;
• these TBMs should have the same reference level as the existing topographical bench marks;
• the TBMs should preferably be set around the perimeter dike;
• the TBMs should be well fixed and protected during the whole construction period.

Stake out ponds and canals and establish temporary bench-marks

4. The construction of one or more ponds and structures can then be initiated, following a sequence which varies according to the type of pond, as suggested in Table 50. Not all the steps are necessary in all cases, but depend on the farm design and the kind of structures to be used.

TABLE 50  Usual order of pond construction phases Construction phase Sunken ponds Barrage ponds Diversion ponds Without diversion canal With diversion canal Diversion canal/main feeder canal - - 1 7 Temporary diversion of stream - - 2 - Pond inlet(s) - - 3 11 Secondary feeder canal(s) - - - 8 Main water intake - - - 9 Barrage on stream - - - 10 Pond dike(s)         foundation 3 6 8 1 construction 4 7 9 6 forming 5 8 10 12 grassing 6 9 11 14 Pond bottom levelling - - - 13 Pond outlet(s)         excavation of pit(s) - 1 4 2 construction of structure(s) 1* 2 5 4 refilling/compacting pit(s) - 3 6 5 Spillway(s)         mechanical spillway 2* 4 - - emergency spillway 7* 5 7* - Drainage canal(s) - - - 3 * If necessary

5. You may need to change the order of construction in particular circumstances.

(a) Under swampy conditions or whenever the flooding of the site is to be avoided, it is best to build the drainage system of the farm first.

(b) Whenever the ground is flat (slope less than 0.5 percent), it may be easier to build the drainage canal first, then the inlet canal and then to adjust the levels of the pond dikes and bottom accordingly, at an intermediate elevation.

(c) For small artisanal ponds, it may be easier to finish building the dikes before building the pond outlet. Then you need to cut the dike, put in place the outlet structure, and then rebuild the dike on top.

Sunken pond		Diversion pond
Barrage pond without diversion canal		Barrage pond with diversion canal

6. On the basis of this information, prepare a schedule of activities showing:

• along a central line, the order in which the indispensable activities are to be implemented; and
• along lateral lines, the complementary activities, which can be implemented simultaneously with some indispensable activities.

Schedule of activities

7. You can improve this schedule of activities by adding a background time scale (in weeks for example) and by showing for each activity:

• when it is planned to take place; and
• how long it will take.

8. To do this, use the working standards which are given in the next section together with your earthwork estimates and the list of structures to be built.

Schedule of activities on a week basis

12.7 Working standards for planning purposes

1. You will use working standards both before construction starts and during its execution, for example:

• to estimate the number of labourers and how long you will need them for each construction phase;
• to select the type of earth-moving equipment and to estimate for how long you will require it;
• to estimate how much the construction will cost you and, if necessary, to discuss with a contractor the price being proposed.

2. In the following paragraphs, general standards useful for fish farm construction are provided.

Working standards for manual earthwork
3. These working standards will vary mainly with the nature of the soil. The harder the soil, the more difficult it is to work it and the lower the work outputs. The presence of excess water also decreases outputs, particularly in heavy and sticky clays.		Manual earthwork

Example  Working hours for manual construction of rural ponds   Farm 1* Farm 2**  Farm 3*** Main water intake with small dam on stream 130 266 130 Feeder canal (200 m) 50 (200 m) 50 (270 m) 70 Excavation/dikes construction (150 m3) 600 (400 m3) 1600 (950 m3) 3600 Inlet/outlet pipes 5+ 4 90+ Total working time 785 1920 3890
	* One 400 m2 diversion pond ** Two 200 m2 diversion ponds *** Four 400 m2 diversion ponds and two 100 m2 diversion ponds + Including concrete

4. When planning earth movements, you should take into account that to minimize costs, distancesshould be limited as follows: horizontal distance for throwing earth: maximum 4 m; vertical upward distance for loading earth: maximum 1.60 m; oblique distance for loading earth: maximum 4 m.

5. Working standards for earthwork with manual labour are given in Table 51. These are the average outputs to be expected from labourers of average strength working for eight hours at digging and throwing the earth 1 m away. The minimum values are for excavating and throwing 1 m away by hoe. The maximum values refer to the use of pick and shovel under similar conditions. These outputs should be slightly reduced as the throwing distance increases.

6. For excavating and forming canals, the output for a trained labourer varies from 0.8 to 1.2 m³ /day.

TABLE 51  Average output of manual labour for excavations Nature of soil Volume excavated/thrown away (m3/8h) By hoe By pick/shovel Soft (alluvium, sandy soil) 2.5-3 3.5-4 Moderately hard (loam, light clay) 1.5-2 2.5-3 Hard (heavier clay) 1 2-2.5 Lateritic, moderately hard* 0.5 1-1.5 Water saturated 0.8-1.5 1.5-2 * See Section 18, Soil, 6.

7. The nature of the soil determines the excavation method. If the soil is soft, it may be possible to work with a shovel only. If the soil is harder, it is best to first use a pick to loosen the soil before shovelling it away. In this case, the following outputs can be expected for each team of labourers:

Soil Labour and tools Output (m3/hour/team) Normal 2 labourers = 1 pick + 1 shovel 0.8-1.0 Light 3 labourers = 1 pick + 2 shovels 1.5-2.5 Heavy/wet 3 labourers = 2 picks + 1 shovel 0.4-0.6

Working standards for transporting earth with wheelbarrows

8. A standard metal wheelbarrow can transport from 30 litres (0.03 m³) to 60 litres (0.06 m³) of earth. Preferably, you should limit the transport distance to 30 m at the most. For planning purposes, you can then calculate the following:

(a) Estimate the number N of earth loads to be transported over a short distance per working hour as

N = 60 min ÷ (loading time + transport time)

where 

loading time averages 1.5 minutes per load; and
transport time is based on the total distance to be covered and an average walking speed of 50 m/min on level ground or 40 to 45 m/min on sloping ground carrying the full load uphill. Downhill slopes will similarly increase transport speed.

Note: it is possible to reduce average loading time and even make it zero by using many wheelbarrows.

Example

You transport earth on level ground over a distance of 20 m. Per working hour, you will be able to make:
N = 60 min ÷ [1.5 min + (40 m at 50 m/min)]
    = 60 min ÷ (1.5 min + 0.80 min)
    = 60 min ÷ 2.30 min = 26 trips

(b) Estimate the amount of excavated earth you can load in one wheelbarrow, for example 0.045 m³.

(c) Estimate how many effective working hours there will be for each working day, taking into account resting periods, which normally total about 25 percent. For example, each eight-hour working day may provide six effective working hours.

(d) Estimate the earthwork volume to be moved daily for each wheelbarrow from the above figures.

Example

• Number of trips per effective working hour = 26
• Effective working hours per day = 6
• Excavated earthwork per wheelbarrow = 0.045 m³
• Earthwork volume moved daily per wheelbarrow = 26 x 6 x 0.045 m³ = 7.02 m³ or about 7 m³

(e) To service each wheelbarrow for transport distances up to 30 m, you will need at least:

one worker to dig and fill the wheelbarrow; and one worker to push the wheelbarrow.

(f) You might need additional workers at particular spots:

• at the dumping site, to assist emptying the wheelbarrow completely;
• along the transport road at climbing points, to help bring the wheelbarrow up the slope.

Average output of various types of machinery

9. Working standards for the most commonly used earthworking machinery are given in Table 52. These machines are particularly useful if relatively large areas of land are involved.

10. Bulldozers' output increases as the engine power increases, as shown in Table 53. These are approximate outputs for normal soil conditions and for a maximum transport distance of 50 m by pushing. Lower outputs should be used as soil conditions worsen, for example in heavy/sticky clays.

Example

One contractor calculated the average time necessary to construct one 2500 m² diversion pond, as part of a 5 ha commercial farm as given here.

Item Machinery/labour Working time (hours) Ripping/removing topsoil Bulldozer D4 13 Excavation/dikes construction Bulldozer D8 56 Levelling dike tops Bulldozer D4 8 Levelling pond bottom Grader 6 Compaction of dikes D4 + roller 12 Finishing dikes 6 men 32 Monk construction 4 men + concrete mixer 32 Inlet construction 4 men + concrete mixer 32

TABLE 52  Average output of various machinery per working hour

TABLE 53  Approximate output of bulldozers for earthwork Approx. power rating (horsepower) Approx. blade capacity* (m3) Excavation/transport** (m3/h) Spreading loose earth (m3/h) 40 1.2 13-17 18-24 70 2.5 22-29 30-39 90 3.6 32-40 42-54 130 4.0 46-71 60-76
	* When completely filled. In practice, filling is usually 30 to 60% of this, depending on site conditions ** Excavations by layers less than 0.5 m thick. Transport over 50 m at most, in good site conditions

Bulldozer		Wheel loader
Compactors

Working standards for construction of structures

11. To build a brick wall (half-stone pattern), you will require about 50 bricks per m² . A good mason can place at the most 600 to 800 bricks per eight-hour day. Note, however, that walls should not be built up more than about 50 cm/day.

12. To mix and cast concrete, the required labour varies from eight work-hours/m³ (without reinforcement) to ten work-hours/m³ (with reinforcement).

Note: it is possible to estimate output by defining the time for each trip based on: excavation of blade load 0.5-1 min; pushing, 2 km/h; returning 4-5 km/h; turning, positioning, gear change 0.5-1 min; allow a maximum of 50 minutes per hour utilization. These output figures decrease considerably in difficult site conditions such as sloping ground.

12.8 Estimating the cost of construction

1. The construction costs of fish farms vary considerably from place to place, depending particularly on such factors as:

• the topography of the site: a gentle slope can reduce earth transport;
• the type of soil: swampy sites are the most expensive-,
• the kind of materials to be used: concrete can be cheaper than wood;
• the fish farm layout: it is cheaper to build larger ponds;
• the way you choose to construct: it may be cheaper to organize the work yourself;
• the rate at which you do the work: it is usually cheaper to plan the work according to the capacity of locally available workers and equipment.

2. By estimating the cost of several alternatives, you will be able to compare them and select the cheapest way. A good solution to reduce the overall cost of the fish farm is to reduce the cost of its structures, for example by fitting the plan as well as possible to the local conditions, choosing a cheaper material and planning for smaller, better adapted structures. You can also reduce cost bydeveloping the farm stage-by-stage, so that earnings from early production can help to pay for later stages of construction. While trying to save on construction costs, beware of:

• reducing the quality of the structures, which should remain good in all cases; and
• trying to save money on the cost of the dikes, especially for a barrage pond.

TABLE 54  Useful life and relative maintenance costs on fish farms Item Useful life (years) Relative maintenance cost* Earthen ponds 25-50   Pond structures     hard wood, treated 10 (3) masonry 20-25 (2) concrete 20-25 (1) Earthen canals 30-50   Well 15   Pump 10-15   Fuel tank 20   Service buildings 20   * The higher the number, the greater the cost

3. When deciding on which materials to use, it is also important to take into account the useful life of the structures (Table 54). As the useful life increases, the annual depreciation cost of the item (original cost ÷ useful life) decreases, (see Section 16.7, Management, 21).

4. Maintenance costs can also vary according to the type of material used for the construction of a structure. They increase, for example, from concrete to masonry to treated hardwood.

5. Major items of cost for the construction of a fish farm include site preparation, pond construction, water control structures and water transport structures. Other costs may include detailed topographical and soil surveys, pegging of the construction works and miscellaneous expenses such as the settling basin, protection canal, access roads, fencing and service buildings.

6. Additional structures can be constructed according to the needs of the management of the fish stocks such as harvesting and feeding. This is discussed in detail in Management, 21. You shouldcalculate the cost of each item separately. A first estimate of the total cost is obtained by adding all these individual costs together. The final estimate is this first estimate increased by 10 to 15 percent for contingencies.

7. For manual construction only, the cost estimate is based on the working hours required and on the materials to be used. Whenever machinery is involved, individual cost estimates are obtained as follows:

(a) Site preparation:

• site clearing: price is essentially based on the density of the vegetation cover and on the average size of the trees. If possible, the wood can be sold either processed (e.g. charcoal or planks) or unprocessed;
• topsoil removal/storage: price is based on the depth of excavation, the surface area and the transport distance;
• levelling: price is based on the depth of excavation and surface area.

(b) Pond construction, where the dikes' volume should be equal to excavation volume:

• excavation volume: price per m³;
• transport distance: price per m³ according to distance (in m).

Note: average transport distance d can be estimated according to the local topography and the pond width w, somewhere between d = 0.25 w for flat ground and d = 0.66 w for steep slopes.

• compaction: price either per m² of dike or per m³ of earthwork;
• finishing: price per m² of dike.

(c) Water control structures, where the individual price is determined according to quantity (length/weight/volume) of materials needed and unit price of each material, plus labour cost for construction.

(d) Water transport structures, where the price of the excavation and forming of water canals is calculated according to excavation volume.

Example

A paddy pond 20 m x 20 m = 400 m² is to be constructed on a flat area of land, with the dikes' cross-section being 2.50 m² . The vegetation cover consists of cleared rain forest and the topsoil to be removed is 0.20 m deep. The structures are:

• inlet = 1 m concrete pipe with diameter 0.15 m;
• outlet = concrete monk (1.50 m high) on concrete foundation; total concrete volume = 0.34 m³ ; concrete pipeline is 5 m long with 0.20 m diameter;
• feeder canal: 50 m long with 0.1 m³ cross-section.

Construction cost estimate for this 400 m2 paddy pond is obtained as follows: Item Unit Number of units Cost per unit (US$) Cost of item (US$) Site clearing m2 400 0.25 100.00 Top soil removal/storage (0.20 m) m3 80 2.50 200.00 Earthwork         pond dikes (80 m x 2.50 m2) m3 200 1.60 320.00 feeder canal (50 m x 0.10 m2) m3 5 1.60 8.00 drainage canal (20 m x 0.10 m2) m3 2 1.60 3.20 transport on 5 m average m3-m 1000 0.0012 1.20 compaction m3 200 1.00 200.00 finishing: forming/planting m2 160 0.50 80.00 Monk tower structure m3 0.34 103.40 35.16 Monk pipeline m 5 1.70 8.50 Inlet pipe m 1 1.40 1.40 Construction cost of pond       957.46 Contingencies (approx. 10%)       95.75 Total cost estimate       1053.21