Tilapia Pond Team
March 2011 Montaña de Luz Documentation March 3, 2011
Written By:
Amelia Quilon Laura Reisenauer Matthew Morelock Mike Guthrie
Table of Contents 2
I. Introduction/Background ……………………………………… ….Page 3
II. Problem Statement ………………………………………….……. Page 4
III. Initial Project Planning ……………………………………….…. Page 5-7
IV. Plans for Implementation…………………………………….……Page 8-9
V. Schedule while in Honduras……………………………………….Page 10-11
VI. Expenses…………………………………………………………...Page 12
V. Objectives Achieved……………………………………………….Page 13-15
VI. Future Recommendations……………………………………….....Page 16-17
VII. Packing List…………………………………………….………...Page 18
VIII. Useful Spanish Words………………………………………..….Page 19
IX. Team Agreement………………………………………………..…Page 20
X. References………………………………………………………… Page 21
Appendix A – Instruction Manual Outline…………………………….Page 22-31
Appendix B – Basic Spanish Instructions …………………………….Page 32-33
I. Introduction/Background 3
In the past, Montana de Luz (MdL), an orphanage for children with AIDS and HIV, decided to start a tilapia pond. A tilapia pond is an above or underground pond that is stocked with tilapia, a hardy fish that can live in varying conditions. Many small ponds are used to provide a protein source for the family or organization that uses the pond. Other large ponds produce enough tilapia when they are harvested to sell in the market in order to make a profit.
The pond at MdL was constructed and was used for three years before it was shut down. When we asked the current staff why the pond was shut down, they replied that the past staff at the time decided that the cost of running the pond was too high for the amount of fish produced. The majority of the cost was determined to be linked to the electricity needed to run the pump in order to aerate the pond. Due to the cost of maintaining the pond and the lack of profit coming from harvesting the fish, management decided to cease the project.
In 2010, a team with ECOS traveled to Honduras and assessed the current pond. They evaluated the current pond at MdL that was previously used for a tilapia pond and determined that the current pond was not designed efficiently to produce tilapia because the pond was too deep. The current depth made aeration a large issue. The team suggested constructing a new pond that would be much more shallow (they suggested a meter) and located near the chicken coop. They recommended this because the area was clear and available for construction and the location was in close proximity to the chicken coop, suggesting that chicken scraps and waste could be discarded into the tilapia pond to be used as food.
II. Problem Statement 4
After evaluating the background information of the tilapia pond, we decided to first develop a problem statement/definition. This problem statement is as follows.
MdL’s past experience with the tilapia pond was negative. The past pond was too
expensive and was thus shut down. Therefore, any future ponds must be more cost
efficient in order to promote the project. This may include aeration, feeding techniques,
harvesting techniques, and any other areas that may have respective costs. The past pond
was also designed inefficiently, lacking any concern for the needs required to maintain a
successful tilapia pond. The past team suggested constructing a completely new pond,
but with that construction comes many risks and costs. Therefore, we must also
determine the benefit of keeping the old tilapia pond or constructing a new tilapia pond.
We must also ensure that whatever route we decide to take is sustainable for MdL.
Another issue is whether MdL desires to continue the project of the tilapia pond. We must
therefore determine the benefit versus the cost. These benefits include an additional
protein source for the kids and a future profit. This is expanded under the Initial Project
Planning section.
III. Initial Project Planning 5
Our initial problem was that MdL’s experience with a tilapia pond was mostly negative.
Therefore, our first goal in our initial project planning was to convince ourselves first that the pond would be beneficial for MdL. After determining that a tilapia pond provided many benefits for MdL, we then proceeded to ask the staff at MdL what their opinion on the project was.
Alexandra Russo, who is a staff member in Honduras with MdL, replied that the staff would like to proceed with the project so that we could achieve a working tilapia pond on site at MdL. She replied that they would like to use the pond to harvest tilapia to increase the protein in the diets of the children and if possible, an external profit. Alexandra also suggested that our team discover a more energy efficient aeration method of the pond, since that was a major issue in the past.
Our next issue with our problem statement was the decision to either use the current pond or to construct a new pond near the chicken coop. We weighed the different consequences with each option. A new pond would allow us to construct it more optimally for tilapia production and would provide a better location near the chickens. However, this option would likely increase the costs of the project. Using the old pond would require us to alter the construction of the existing pond to make it more efficient for tilapia production but would likely cost less than constructing an entirely new pond. When brainstorming this issue, we contacted Laura Tiu, an Aquaculture expert at The Ohio State University. She mentioned that we should focus on a small scale project instead of diving into a large scale project. This was one of the main viewpoints that influenced our further planning for our project.
At this point, we decided to focus on using the existing pond’s structure instead of creating a newly constructed pond. Constructing a completely new pond would increase the project costs, thus increasing the risks. Therefore, using the existing pond would decrease risks 6 and allow us to use the pond as a test run to prove to future groups and MdL that a tilapia pond is feasible and beneficial.
After deciding that we were going to use the existing pond, we then had to determine how we were going to alter the pond’s structure in order to make it more efficient for tilapia production. Our first idea was to fill the pond with dirt to a more optimal depth (so that the depth of the water would be around 1 meter) and then to cap the pond with concrete. After reviewing this option, we discovered that this would be extremely costly. After determining that this option would be too expensive, we weighed other ideas. Our next idea was to fill the pond 1 meter with water and to then build a catwalk or step system that would allow Saul (the maintenance manager at MdL) to harvest the fish and maintain the pond more easily. We determined that this option would not be as expensive and would therefore, be more cost effective and would make the pond more efficient.
After determining our plan for reconstructing the pond, we then had to tackle the issue of aeration. In previous years, MdL used a pump during the day and night to aerate the pond. This was the main source of cost for MdL and the deciding factor when shutting the pond down. We then had to brainstorm various solutions to this. Our first idea was to use aquatic plants to aerate the pond during the day. We decided to use algae and duckweed; the two plants, through photosynthesis, would produce oxygen during the day as well as a food source for the tilapia.
However, during the night the process is reversed and the plants use up oxygen. Our next issue was to determine how we would aerate the pond during the night. We considered a solar powered pump, but this would not run during the night. Therefore, we decided to consider a solar powered battery that could store energy during the day that would then be used at night to provide power for the pump. After doing a cost analysis on this idea, we determined that this 7 plan was not cost effective and would require a better assessment of the area and plan. Our meeting notes for these discussions can be found on the MdL Wiki site. Our final idea was to find a more energy efficient pump. After researching various pumps, we decided to go with the
Hakko 120L Air Pump. This pump is energy efficient (using the same amount of energy as a light bulb) and was more cost effective.
Another problem that we faced was the sustainability of our project. We wanted to ensure that the project was successful and could continue to be successful in the future. In order to ensure the sustainability of this project, we decided two factors. The first is the documentation of our project (the final version of our documentation) that future groups could use as a reference when doing further projects of the tilapia pond. We also plan to construct an instruction manual that we will leave at MdL. This instruction manual will include all of the necessary pieces of information MdL will need to continue the tilapia pond’s success. The plan for the instruction manual can be found in the Implementation Plan section. An outline for the instruction manual can be found in Appendix A. We will fill out and complete this outline while in Honduras.
II. Plans for Implementation 8
During our stay, we plan on completing two important tasks.
The first task is to reconstruct and modify the old pond in order to provide a more suitable environment for the tilapia. First, we must assess the overall condition of the pond. This includes repairing any cracks in the concrete first to ensure the pond retains water. After repairing the concrete, we’re going to construct infrastructure on the bottom of the pond that will make harvesting easier. We’re planning on constructing a form of dock or catwalk.
Once these steps are finished, we plan on visiting the University of Zamorano to learn more about tilapia aquaculture. We hope to learn more about how tilapia ponds are managed in
Honduras and the best conditions for raising tilapia in regards to food, water quality, and species.
In addition, we plan on making purchases at Zamorano that include fingerlings, food, and nets.
One of our main problems with the tilapia pond in the past was aeration. In the past, MdL used a pump as their primary source of aeration for the pond. However, after realizing that electricity costs were an issue, we looked for alternative solutions. One solution was to use plants during the day that through photosynthesis, would produce oxygen for the tilapia. However, during the night, plants use up oxygen rather than produce it. Therefore, we decided to implement a new pump for the pond.
The pump we decided on is more energy efficient and will cut down electricity costs for running the pond. The pump will only need to be run during the night which will also cut down on electricity costs.
Our second task is to create an instruction manual that will detail procedures on testing the water, feeding the fish, harvesting the fish, and overall maintaining the pond. Our hope is that this task will outline for MdL how to care for the pond so that it is sustainable. This manual will include testing procedures to ensure that the water quality remains safe for the tilapia. 9
Analysis will be conducted on the pond in the form of several tests. Tests will check for pH levels, ammonia/nitrite levels, oxygen levels as well as tilapia feeding habits. These tests will be initially conducted by the OSU team while in Honduras, then taught and outlined in the manual for MdL to reference to continue in the future. Harvesting techniques and suggestions will also be included in the manual. An outline of the manual can be found in Appendix A.
III. Schedule
Saturday
. Arrive . Tour MdL 10
Sunday
. Excursion day
Monday
. Visit Zarorano . Patch cracks in the center of the pond . Cleaned middle section of pond . Claudio visited MdL
Tuesday
. Cleaned other two sections . Patched cracks in two sections
Wednesday
. Harwarestor – water tank, PVC . Filled middle section of the pond . Filled third section of the pond . Started documentation . Installed pump . Tested Backup system Thursday
. Unclog water pipe . Refilled pond (lost some water during night) . Tested water height . Claudio and Angel came with fish . Received manual for aquaculture/tilapia
Friday
Tested water
Bought fry food
Built barbed wire fence with Saul
Saturday
. Departure 11
IV. Expenses
1. Pump System
i. Hakko 120L Pump = $325 12
ii. 50ft sinking hose = $150
iv. 12” Air Disc = $75
v. Shipping = $35
Total: $585
2. Concrete Patch Material
i. Hydrolic Cement: $15 (x2) = $30
3. Back up System
i. Water Storage Tank = $125
ii. Piping = $3
4. To be purchased: additional pump parts: $100
5. Testing Kits:
i. pH, nitrites, nitrates testing kit: $12
ii. Ammonia Detox: $25 (in case of high ammonia)
iii. Ammonia Test: $17
V. Objectives Achieved
The main goal for Team Tilapia was to reinstate a working Tilapia pond at MdL. The old pond had been abandoned and had been becoming under a constantly greater state of disrepair 13 for the last three years. There were multiple cracks, some of which extended for several feet, that needed to be repaired. In addition to this, the larger part of the pond contained its own ecosystem, including frogs and a venomous snake, that had to be cleared out before any work could be done to the pond. The team made use of a bucket system to remove the stagnant water and various creatures from the pond.
Figure 1
Once the pond was cleaned out, the team worked to fill the cracks with hydraulic cement.
However, when the middle section of the pond was filled, water still leaked into the larger portion of the pond through the cracks. The hydraulic cement was unable to withstand the water pressure. Since both sections of the pond will usually be filled to an equal height, the water pressures will be equal; thus the cracks have been determined not be a problem.
The team also worked on making the pond a suitable habitat the fish by working to provide ways to aerate the pnd. In order to do this, the team brought an aeration pump to the orphanage. However, since power outages are a weekly occurrence at MdL, the pump may not be able to be run whenever the fish need more oxygen. Therefore, a back-up aeration system that 14 is not dependent on electricity was designed. The pipe and water storage tank that were needed for creating the back-up system were purchased and a copy of the plans for the system will be sent to MdL staff. Saul agreed to build the back-up system after the team returned to America.
Figure 2 In addition to preparing the pond for Tilapia, the team visited Zamorano University to learn more about Tilapia. The team was able to talk to Claudio Castillo, an instructor in Tilapia farming at
Zamorano, and have him come visit MdL to survey the pond. Through Claudio, the team was
Figure 3 able to learn about Tilapia farming practices in Honduras, get recommendations on how many fish to stock the pond with, obtain a textbook (written by Claudio) on Tilapia cultures in
Honduras and obtain about five hundred fry. The team and MdL staff were also Claudio’s dinner hosts on two separate occasions. On the second occasion, the day that Claudio brought the fish to the orphanage, the team also invited Angel Pena, a student of Claudio’s who released the Tilapia in the pond, to dinner. Thus, the team was able to begin forming a working relationship between
MdL and Zamorono University.
Once the fish were in the pond, the team tested the water to be sure that the ammonia, nitrate and other chemical concentrations were at acceptable for the fish. All of the test results showed that the water did not contain any unhealthy levels of contaminates.
It should be noted that the team never inserted steps or a catwalk as had been originally discussed in the planning stages. At Zamorano University the experts drain the pond and then walk around dragging a net collecting fish. Claudio recommended doing this. Therefore, since the pond is planned to be drained at harvesting time and that is the only time anyone should need to go down, a catwalk was deemed unnecessary. In addition to this, building steps would have 15 been a waste of resources because Saul can use a ladder to descend into the pond since the pond will not be full of water.
VI. Future Recommendations
Next year’s team should reassess the pond in terms of MdL’s satisfaction with it, needed maintenance, and possible improvements. Before going down to Honduras, future teams should communicate with MdL staff to be sure that the pump is still working, the pond is well stocked, and the back-up system is operational and effective. Teams should also inquire about MdL staff’s satisfaction with the current pond. In particular, check to see if Saul is satisfied with the pond’s condition, yield, and methods for taking care of the fish. If any of these areas do not meet the staff’s, particularly Saul’s, expectations, then those areas should be worked on. 16
All of the maintenance items should also be checked in person. This includes checking the pond for leaks, testing the back up system, and testing the chemicals in the water. Future teams will need to bring basic ammonia and nitrate testing kits to check that the concentrations of the chemicals in the pond are acceptable for the fish to live in. These can be purchased at many aquarium stores in Columbus.
Once all maintenance items have been taken care of, teams should explore making the current pond more efficient. Ideas for this include investing in a solar powered pump and beginning to run the Tilapia pond with other systems such as the garden and the biodigester.
Extra water from the pond can be used to fill the biodigester or water the garden. Extra food from the garden can be used to feed the Tilapia.
The idea of building a new Tilapia pond has been recommended by previous project teams in. We conditionally extend the recommendation. Since there is now an operating Tilapia pond, taking care of the current pond and the fish should be the first priority. If enough time remains and MdL remains interested in expanding their fish farming, teams may pursue constructing a new pond. Suggested areas are by the chicken coop or by the front gate Teams should keep in mind that this is probably a project that will have to be started on early in the quarter and may take multiple trips to complete. 17
VII. Packing List
List of Necessary Materials
. Tape Measure
. Calculator
. Camera
. Journals . CD’s . Binder with Dividers and Logs . Writing Utensils 18
. Tilapia Pond Materials o Testing Kits o Concrete Patching o Pump
VIII. Useful Spanish Words
Water El agua Project El proyecto Pond El estanque Sustainable Sostenible Assessment La evaluacion Fish El pez Size Tamano Cement El cement Dirt La tierra Quality La calidad Feed Alimentar Test Probar Leave (behind) Dejar 19
Instructions Instrucciones I understand Si entiendo I don’t understand No entiendo What do you think? Que te parece? Do you have any questions? Tienes preguntas? Hammer El martillo Drill El taladro Screw Driver El destorillador Screw El tornillo Nails Las puntillas Hose La manguera Outlet Toma corriente, enchufe Wood La madera Wall El pared Floor El piso
IX. Team Agreement 20
X. References
Dobler, Peter et al. "Water and Agriculture Team." OSU Engineering for Montaña de Luz. OSU Engineering, 21 Apr 2010. Web. 12 Jan 2011.
"Tilapia Farming Basics." Tilapia Farming at Home. N.p., n.d. Web. 14 Feb 2011.
Doudican, Brad. Personal Interview by Tilapia Team. 23 Feb 2011. 23 Feb 2011.
Emanie, Bo, Dir. Fresh Tilapia Harvest. youtube: 2008, Film.
"How to Grow Duckweed." eHow Home. eHow, n.d. Web. 16 Feb 2011.
"How to Grow Algae." eHow Home. eHow, n.d. Web. 16 Feb 2011.
"Raising Tilapia in Your Backyard." AgriBusiness Week. Mindanao Baptist Rural Life Center Foundation, 16 Sep 2008. Web. 16 Feb 2011.
Russo, Alexandra. "Tilapia Pond." Message to Amelia Quilon. 07 Feb 2011. E-mail.
Tiu, Laura. "Information about Aquaculture." Message to Laura Reisnauer. 16 Feb
2011. E-mail.
Saul Caceres. Personal Interview. Date TBD.
Castillo, Claudio. Personal Interview. Date TBD.
Appendix A – Instruction Manual Outline
Tilapia Manual Outline
A. Sustaining the Pond
1. Initial Preparations
The initial observations of the pond included standing water as well as cracks in the concrete. The cracks were patched with quick-crete which was left at Montana de Luz to be used in case cracks develop in the future. The initial state of the pond can be seen in figures A1 through A3. 22
Figure A1: The smallest section of the pond
Figure A2: The middle section of the pond 23
Figure A3: The largest section of the pond
After filling the pond with water, the water level was observed to decrease significantly over the first day and night. This can be seen below in figure A4. The water loss was hypothesized to be caused by the dry concrete and ground surrounding the pond. After two consecutive fillings of the pond the water level stabilized and should not leak much any more. Water loss is a problem, but can be solved by consistently refilling the pond with water every couple weeks or so. It was recommended by the tilapia team to fill the water level about a half meter above the desired height, and then refill it again once the water level dropped below the desired level.
Figure A4: Visible water loss after one day 24
2. Testing
i. pH Testing/Ammonia/nitrite/nitrate Testing
A short supply of pH/Nitrogen tests were purchased by the team and left at MdL for further use. The test is simple and the instructions are on the box. This test should be run about once a week or so. Descriptions of the tests and what to do if they are not returning desirable results can be found at the team’s wiki page at:
http://ecos4mdl.pbworks.com/w/page/36465651/Testing-Procedures
ii. Oxygen Levels
The team did not purchase an oxygen test because they were difficult to find. Claudio had a device that he brought to the pond that measured oxygen levels, but it was a very specialized device and was expensive. A simple way to measure the oxygen is to observe the behavior of the fish, if they are swimming to the surface and “gulping” then they need more oxygen. The pump should be run longer or water should be added to the pond. The pump is currently set to run for five and a half hours each night and works on a timer that was demonstrated to Saul.
iii. Feeding Habits
a. Food Concentrate
This was the primary recommendation of our contacts at Zamorano. The type of concentrate is 28% and needs to be a finer consistency when it is fed to small fish. The first bag that was purchased was too large for the fingerlings to eat, and the pieces had to be crushed to feed them. The correct type of concentrate can be purchased down the road from Zamorano at a pet food store. David at MdL is in charge of the pond and knows where this concentrate should be purchased. 25
The fish should be fed until they stop eating according to Claudio. Simply throw the concentrate in the pond and observe when the fish stop eating because as Claudio and Angel from Zamorano put it, they basically know when they are full.
b. Algae/Duckweed
It was advised to not use algae by the contacts from Zamorano because it only complicates the oxygenation process. They did say that algae would naturally form in the pond and does not need to be grown any specific way or removed from the pond.
c. Chicken/Human Scraps
Tilapia eat a lot so other scraps could be used as food for the fish, but the concentrate is not extremely costly and is truly the best source of nutrition for the fish to grow large. Food scraps could be used as a supplement if concentrate is low, but it is advised to stick to a mainly concentrate diet for the fish.
3. Draining the Pond
i. Techniques for Draining Pond
Saul showed our team the old pump that was used to circulate the water in the pond. It was attached to PVC pipes which branched out to the different parts of the pond. The smaller two sections had actual drains with grates on them that connected to pipes that eventually led to the pump.
26
The largest section had several PVC pipes that extended into the pond at different locations. These pipes hung down far into the pond and were directly attached to the pump. It appeared that one of the PVC drains did not work so another was installed.
In the largest and lowest section, an overflow pipe was installed at the top of the pond to drain any excess water before it spilled over the pond edges. It can be seen at the bottom right of Figure A3.
All of the pipes led to an outlet outside the fence from the pond to a very dry area with little vegetation.
The pump that circulates the water rests under a small roof right next to the largest section of the pond. This can be seen in figure A5 below. It still functions well according to Saul, but does not have a conventional plug and instead must be wired directly for power. Saul showed us that the closest place to wire them was on a large pole standing in the area just above the pond. Saul is knowledgeable about how this has worked in the past and we left it up to him to wire this pump.
Figure A5: Roof covering Circulation and Aeration Pump 27
ii. Uses for excess pond water
a. Biodigester
The drained pond water can be used for keeping the material inserted in the biodigester at the right consistency. For the exact amounts of how much should be used, the Biodigester team documentation should be referenced.
b. Watering the Garden
It was also discussed that the excess water could be used to water the garden. The only issue with this is that the garden is uphill from the pond and it would be difficult to transport all of the water. Brad Doudican first suggested the alternative of panting a garden directly next to the pond so that the pond water would not have to be transported far. The area next to the fence would also be a potential site for a garden.
B. Harvesting Tilapia
1. Techniques
Claudio recommended purchasing a net in Tegucigalpa to harvest the fish. We left Saul and David should be in charge of obtaining the materials necessary for this.
When it comes time to harvest, the water should be drained from the pond to make it easier to gather all of the fish, then refilled with the new fish. 28
Our team recommended to Saul to create some type of platform within the pond to make it easier to reach the fish in the water. He liked the idea, and said that he has the metal and other materials to create this. We left some sketches and the rest is up to Saul and David if they find harvesting the fish is too difficult without a platform.
2. Frequency
The fish should be harvested about every 6 months. If some of the fish are still too small at this point they can be left for longer in the pond to develop. Because the pond is partitioned to three sections, it is recommended to stagger the harvests of each section, so that harvests could be made every 3 months; when one section is ready to be harvested, the other section should have half-way developed fish.
3. Uses for Tilapia
i. Food Source
The aquculture book provided detailed explanations in Spanish on how to filet and prepare the fish for eating. A technique that may be suggested to MdL that was demonstrated on the Backyard Tilapia Farming website was putting the fully grown fish in a new pond of cleaner water right before harvesting them to give the fish a fresher taste.
ii. Profit
The towns right below MdL of Nueva Paraiso and Nueva Esperanza contain many small pulperias and food stores, and past groups at MdL have helped create a store to be used to sell items grown and harvested at MdL. It is highly recommended that the fish that are not eaten by the orphanage be sold at this store for a profit. Because the fingerlings are bought at 40 centavos a piece, and concentrate is the only continuing expense the fish could definitely help the orphanage earn a profit.
29
***The aquaculture book given to us by Zamorano as well as Claudio himself should also be used as a reference for questions regarding harvesting, feeding or preparing the tilapia.
C. Expanding the System
1. Uses for other compartments of existing pond
i. Duckweed/Algae Production
As mentioned earlier, it is not recommended to grow algae other than what will grow naturally.
ii. Additional Tilapia (Staging with fingerlings)
As also mentioned earlier, it is strongly recommended to stage the fish in the three compartments of the pond. Fingerlings should start in the smallest section, and as they grow larger they should be advanced to the larger section. Once the more developed fish have been advanced to the larger section, the smaller section should be filled with fingerlings again. This should occur at around 3 months after the original fingerlings were added.
Breeding the fish is a complicated process that requires Zamorano to have many students and equipment to work. Our recommendation is to just buy new fingerlings from Zamorano when they are needed.
2. Above Ground Ponds
30
Our team discussed creating above ground ponds that were more favorably shaped to harvest Tilapia (~1 meter deep and not irregularly shaped). However, our contacts at Zamorano advised against making any above ground structures because they are very reactive to external temperatures. If more tilapia ponds are to be created at MdL, they should be dug in ground . Pond liners or concrete could be used to seal the pond in. Future teams should look into this possibility.
3. Alternative Sources of Aeration
i. Current System
The current pump for aerating the water is located under the small roof right next to the circulation pump. It is connected to Saul’s workshop by two long extension cords and runs several hours overnight with a timer. A splitter was purchased in America and will be sent down to be used in the largest section of the pond as only the middle section has a pump and fish in it currently. The only problem with this system is that it will not work if the power goes out at MdL, which occurs frequently.
ii. Fountain, running water
Materials were purchased at a hardware store right next to MdL to create a back up aeration system. The materials included a 120 gallon water basin with a valve, and three lengths of ½” PVC pipe. The PVC pipe will have many holes cut into it to drip water at a controlled rate into the pond which will provide oxygen for the fish. Saul is knowledgeable about how the system works and demonstrated techniques for cutting the holes in the PVC pipe as well as increasing the water pressure in the tube. He also told us that he has metal and the materials to build a platform for the water basin to be raised up. This system can be refilled with well water if the power is out and should be a fairly reliable backup aeration system if the power goes out for about a day or so. A sketch of the system is shown below in figure A6. 31
Figure A6: Sketch of the back-up aeration system
Our team suggests for future teams to look into more alternatives to aerating the pond without using electrical power. Possible ideas could include solar power, or other varieties of dripping water into the pond. 32
Appendix B
1. Alimentar a los peces dos veces al día hasta que deje de comer (concentrado 28%)
2. Si los peces suben a la superficie para el aire, activar la bomba
a. Si no hay luz, agregar el agua del tanque o el tubo de salida hasta el regreso de peces por debajo de la superficie
3. Después de 3 meses, mover los peces a la sección más grande de el acuario y añadir guapote a la sección más grande. 33
a. Si los peces aparecen atestadas, que se puede mover antes de 3 meses
4. Si el nivel del agua es baja, añadir más agua.