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Water and Agriculture Team

March 2010 Montaña de LuzEng 692

Post-Trip DocumentationApril 21, 2010

Written By:

Peter DoblerChris Ratcliff

Francis KrivankaKevin Kuhn

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Table of Contents

I. Introduction/Goals ……………………………………………… ….Page 3

II. Plans for Implementation……………………………………………Page 5

III. Schedule while in Honduras……………………………………….Page 7

IV. Expenses…………………………………………………………...Page 9

V. Objectives Achieved……………………………………………….Page 10

VI. Future Recommendations…………………………………………...Page 22

VII. Packing List………………………………………………………...Page 31

VIII. Useful Spanish Words…………………………………………….Page 32

IX. Team Agreement…………………………………………………Page 33

X. References………………………………………………………… Page 34

Appendices…………………………………………………………….Page 35

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I. Introduction/Goals

Previous years have made a lot of progress in the area of water filtration at an orphanage

for kids with HIV/AIDS in Montaña de Luz, Honduras. The water system has been tested and

shown to work effectively to kill off most of the bacteria and viruses present in the water. The

presence of arsenic in the water has proved to be an issue and has been thoroughly tested and a

filtration system installed to lower the level arsenic to the WHO standard. A problem with

changing directors at the orphanage has, however, lead to the loss of knowledge of the use and

exchange of filters provided to remove the arsenic. As a group, we plan on educating the existing

directors at the orphanage in how and why it is important to switch out the filters regularly. That

way they can keep up the filtration of the water to keep the children as healthy as possible.

In the past, the orphanage had tried to set up a Tilapia pond in order to get a secondary

source of protein for the children. Problems arose from the design of the pond and the lack of

information needed to sustain the pond. Tilapia is a very resilient species of fish and they tend to

strive in all kinds of terrain. They are full of protein and tend to be a lighter flavor fish, making

them very popular. As of now, the orphanage does not plan on reestablishing a new pond until a

concrete plan of how to run it is made. During our stay at the orphanage we plan to assess the

area in order to create a more definite plan in building the tilapia pond in the future.

The orphanage has an existing garden but it seems to have problems throughout the year.

The extreme heat of the dry season and the pounding rain of the wet season take a toll on the

plants. Also the terraced garden has problems with the rocky terrain and the plants not being able

to get enough nutrients. A compost bin was constructed many years ago to help with the garden

but has not been used due to lack of knowledge of what is supposed to go into it. The design and

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use of the compost bin will be written in an easier and more descriptive way to make it easy for

the orphanage to use the benefits of composting. A garden tarp will be installed over the plot in

order to reduce the amount of sunlight that is allowed to reach the plants and will also reduce the

pressure of the rainfall on the plants.

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II. Plans for Implementation

A. Water QualityWe plan to install new filters in the filtration systems that were brought to MDL in previous

years. Vicki has already offered to order the filters and bring them down to MDL when she goes

a few days before us. The installation of the filters will be done with the aid of instruction

manuals found for the products online. Once installed and functioning, we will make an

assessment of the filter utility with the goal of making them as functional as possible. We know

that the flow rates for these filters can be very slow and that this represents a possible problem

for sustainability. We will try to work out a way to make the filling of drinking water containers

as easy as possible. We will try to get as much input from the staff who will actually be using

these filters as possible. One idea we have is to buy a large reservoir tank that can remain full

and be used to fill drinking water jugs at a faster rate. Another idea is to buy extra drinking

water containers and somehow automate the filling so that they can be filled easily and are

available to replace when needed. Either way, this will probably require a trip to Tegucigalpa to

purchase water containers from a hardware store. Exact plans for this are still being discussed

and may not be finalized until speaking with the MDL staff.

It is unclear to what extent we will be able to test the water at MDL. An arsenic test kit

was brought to MDL by a previous group, but it seems to have been lost when the roof of the

building it was in blew off in a storm. We will measure the chlorine in the water to ensure that

the chlorinator is working correctly.

B. Tilapia Pond

The Tilapia pond assessment will begin with an assessment on the old pond to determine the

feasibility of incorporation with future ponds. We would like to include the old pond in the

design for a new pond to save money and effort if possible. We would also like to learn anything

we can from the old pond. For example how they constructed the pond and how they managed

water leakage. The assessment will also include soil testing, water testing, and surveying of the

property.

We would like to test the soil for water retention capability. We are not very optimistic in

this because we already know the soil to be rocky. This will be done by simply digging a hole

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and filling it with water. We will test a control by digging a similar sized hole and placing a

leak-free bucket inside. We expect to lose water from the pond from evaporation and this will

allow a rough measure of those losses.

The only water test we are concerned with is pH because in certain pH ranges tilapia cannot

live. Other water quality tests are not necessary as extensive water quality data is already

available from work done by previous groups. pH tests can be done simply with litmus paper.

We will need to make sure to test the ground water that has not been chlorinated as the tilapia

pond must not be filled with chlorinated water.

Surveying the property will be necessary for us to make our recommendations for pond

design. We will take notes, measurements and photos of areas on the property where the pond

could possibly go. We will take account of the following design considerations: slope of the

land, the composition of the soil, and the proximity of the location to the chicken coup and the

garden.

The assessment document will be written after we return from MDL and will be a

compilation of all the research we did prior to the trip and all that we learned from being at

MDL. We will translate, as much as possible, the document to Spanish and it will be sent to

Vicki. We will also try to explain, as much as we can, what we have learned to the staff at MDL

who are interested. From this we may gain a lot of insight into different constraints or ideas that

we may not have thought of.

C. Garden

Instillation of a roof for the garden at MDL will take some assessment to determine the

design for the structure. From the few pictures we have seen, it appears that some structure is

already in place, but might not be ideal. The amount of roofing material we will purchase will

depend on what we can afford . We will also purchase some equipment for the support structure

of the roof. The price is listed in the expenses section of this document. Again, the final design

will depend on what we find when we arrive, but we expect to either use extra material available

at MDL to complete the project or take a trip to the hardware store in Tegucigalpa.

We will also write an instructional document on composting before the trip in English and

Spanish to bring to MDL. We will explain the concept of composting to those staff that might be

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involved and try to answer any questions they may have about the process of composting or why

it’s necessary.

III. Schedule

Saturday

Arrive at Tegucigalpa by noon Purchase materials Preliminary investigation of MdL grounds Discuss with staff about availability of local experts (Tilapia Pond, Garden, Water

System). Adjust schedule accordingly. Evaluate progress, plan for Monday

Sunday

Excursion day

Monday

Water Dayo Preliminary tests – test water, check functionality of all systemso Install filter system and cartridgeso Test water again once system is installedo Develop system for water storage using large containero Travel to store for additional materials if necessaryo Evaluate progress, plan for the following day

Tuesday

Garden Dayo Examine MdL grounds, take measurements of garden areaso Discuss roof idea (shade netting) with staffo Install shade nettingo Evaluate progress, plan for the following day

Wednesday

Tilapia Pond Dayo Examine existing pondo Discuss options with staff, local expertso Research available local resources

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o Evaluate progress, plan for the following day

Thursday

Garden Dayo Develop prototype tower garden if desired by staffo Evaluate progress, plan for the following day

Friday

Free Dayo Available time to finish any projects that may have been postponed or were left

unfinishedo Also free to help other teams or MdL staff with remaining tasks

Saturday

Departure

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IV. Expenses

Cost of Materials

Shade Netting for gardeno Greenhousemegastore.com

40% Black Knitted Shade Cloth – 26’x 72’ $246.00 600’ of 1/8’’ black rope $39.00 rope/wire to connect netting $30.00

Water testing kits $50.00 Large container for water $10.00-$20.00

Maximum Predicted Total Cost $385.00

Water Filtration SystemLiving Water Unit- $356.15 (already at MdL)

LW10KCER Cartridge $75.65 6 mo.

LW10CBR/ST.1 Ster-O-Tap Combi Ultrafiltration Cartridge $67.15 4 mo.

LW10FRC $42.08 4 mo.

cost per year: $478.99

Costs for water filtration system covered by MdL.

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V. Objectives Achieved

One of the high priority projects for the team was making the water filtration system in

the kitchen of MdL functional and ensuring that the project was sustained in the future. This

system had previously been researched and installed by several years of previous groups, but was

currently disconnected due to a low flow rate out of the system caused by the lack of

replacement filter cartridges. The system, consisting of three cartridges connected in order and

with an output faucet over the sink, is shown below:

Figure 1: MdL Water Filtration System

Due to the high cost of the current system, the team researched alternative options for

arsenic removal, such as biosand filters, but determined that the current system would be the best

choice for MdL. The team, in conjunction with Vicki Rush, the executive director, determined

that the filtration system in the MdL kitchen was a higher priority than the system in the

director’s house, so two replacement sets of cartridges were ordered for this system. Also, when

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the filters were ordered, a new version of the filters was available, so the documentation was

updated with that in mind.

Since the main problem with the previous projects had been the lack of effective

communication with the MdL staff, this year’s project was largely focused around making sure

that MdL was on the same page and understood what needed to be done to keep the system

functioning adequately. Vicki also assured us that the current staff would sustain our efforts,

since communications broke down when the old staff left and transitioned to the new staff. To

fix this problem, we first made sure that Vicki knew exactly what was going on, then had several

meetings with the staff at the beginning and end of the week to communicate what was being

done. The filters were changed and replaced with the updated models, and the instructions that

came with the filters were put on the wall in the kitchen in the correct order behind the filtration

system so that the staff would easily know without needing to look at documentation where and

how to place the filters. Also, the team documentation that explained the need for the filters, the

appearance, function, and cost of each filter, and ordering instructions for more filters was placed

on the wall in both English and Spanish. These two components are both shown below, and are

designed to make sure that the staff has as much information immediately available to them as

possible so that there is no way they can be unaware of what needs to be done. All this has also

been waterproofed so that it will last.

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Figure 2: Filter Instructions Figure 3: Filtration Information

After the filters were installed, the water was tested with an arsenic kit donated from

Hach to ensure that the filtration process was still effective with the new filters. The results were

extremely promising, with the water before filtration having an arsenic level of about 30-40 ppb

and after filtration with an arsenic level of about 5 ppb, well below the World Health

Organization standard of 10 ppb. These results are shown below

Figure 4: Non-filtered Water Arsenic Test Figure 5: Filtered Water Arsenic Test

Chlorine levels were also tested with the photometer obtained from Dr. Walker to ensure

that there were no unanticipated problems with the chlorination system, but no problems were

observed with the chlorine concentration.

Overall, the water project was a success, and will continue to provide clean drinking

water to the children of MdL with proper limited maintenance for years to come.

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Compost

In order to recycle some of the kitchen waste produced at MdL and use it to benefit the

agriculture of the grounds, research was done prior to the trip on the subject of composting. It

was found that on the grounds of MdL there was an area behind the chicken coop where all of

the waste was stored in rubber bins. This area was not very well kempt – there was waste

overflowing onto the ground. There were also a lot of plastic wrappers and other non-organic

waste found in the bins and surrounding area.

It was decided that more bins should be used for storage of this waste in order to keep the

area cleaner. Additionally, instructions for composting would be shared with the staff at MdL –

more specifically, instructions for what types of materials should and should not be composted.

Dry leaves were collected around the grounds in order to establish a good balance of wet

and dry waste for proper composting. The bins which were already full were to be emptied and

refilled with a layered mix of wet and dry waste. Before this could be completed, however, it was

discovered that MdL in fact had a biodigester installed on the grounds. An example of the type of

biodigester which MdL has installed is found below.

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A biodigester is essentially a large reservoir which allows for the biological breakdown

of organic matter. The organic matter is broken down into two different outputs – biogas and

nutrient rich liquid fertilizer. The top of the reservoir holds the biogas which can be tapped into

and used as cheap fuel. The fertilizer comes out of the side of the biodigester opposite to where

the organic matter is input. Biodigester information is posted on the wiki.

Currently at MdL there is a gas line which travels from the reservoir of the biodigester to

the butchering station, but the gas is not currently being utilized. Members of the MdL staff

wanted to bring back the person who installed the biodigester in order to complete the

installation process and make full use of it, but this had not been possible thus far. Below are

some pictures taken at MdL which depict the various visible parts of the biodigester.

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Waste Bins, Biodigester Input, Biogas Reservoir Tap

Biogas Reservoir Tap, Gas Meters

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Biodigester Output Container Biodigester Output Container

Garden

Through discussions with Vicki, it was discovered that due to the extreme heat of the sun

and the extreme force of the rainfall, the plants in the gardens at MdL struggled and required

protection from the elements in order to survive. The staff at MdL had already begun to build a

roof for the gardens but the project had not been completed. The completed portion included 18

vertical metal poles installed into poured concrete foundations. The poles were in 3 rows with 6

poles per row, and each pole in the middle row was taller than the poles on either side of it.

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There were 6 bent, V-shaped poles that were not yet attached and were to be welded to the

vertical poles to create the basic structure for the roof. Then a material was going to cover the

entire structure, more than likely something similar to the plastic tarp-like material that covered

many of the greenhouses seen in rural Honduras. Instead of completing the welded structure of

the roof according to this plan, however, a different plan was put into place to protect the

gardens.

Holes were drilled at the tops of each of the vertical metal poles. The holes not only

allowed for the poles to be anchored to the walls of the surrounding buildings, but also allowed

for steel cable to be run along each row of poles. The steel cable was purchased from the

hardware store in Tegucigalpa. Shade netting designed specifically for garden use had been

purchased online prior to the trip and was brought down with the group. The netting was

purchased from greenhousemegastore.com and the order amounted to $360.00, including the

bungee cords and plastic ties used for attaching the shade netting. The netting had metal

grommets which were spaced approximately every two feet apart along the edges of the netting.

Plastic ties were then used to connect the shade netting to the steel cables (only a few bungie

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cords were used at the corners). The finished shade netting roof covered a majority of the garden.

One worry which arose after the roof was finished was that since the netting was stretched over

the tops of the poles in the middle row, the netting might tear over time. To prevent excessive

wear on the netting, pieces of plastic weed tarp were placed on the tops of these poles between

the poles and the netting. A diagram of the garden area is given in Appendix C.

The surface temperature of the ground under the shaded area was in fact measured to be

20 degrees (Fahrenheit) cooler than that of the unshaded ground, and this measurement was not

even taken at the hottest time of the day.

Finished Shade Netting Roof Shaded vs. Unshaded areas of garden

Tilapia Pond

Most of the tilapia pond material can be found under the recommendations section since

this group’s tilapia pond project was mainly assessment and nothing concrete was done while at

MdL. However, much was learned while in Honduras about the potential and means of starting a

tilapia operation. The main objectives achieved were analysis of the current pond, analysis of

location and possibilities for a future, better pond, a water evaporation experiment to help

determine cost, and a lot of information learned from discussion with knowledgeable people

about tilapia, namely Saul, the maintenance guy who knows a lot about tilapia, Claudio Castillo,

an agricultural engineer in charge of the extensive tilapia operation at the University of

Zamorano, and Larry Overholt, a mission worker from Choluteca who specializes in aquaponics

systems with tilapia. Following is some of the information determined from on-site analysis as

well as a brief background.

Tilapia pond background

A tilapia pond is a great way to make use of otherwise poor agricultural land. Tilapia would be a

good source of nutrition for the children and staff of MDL as well as the surrounding

communities and a good source of income for MDL.

Some potential problems for a successful tilapia culture at MDL include:

cost of implementation (construction, feeding, etc.)

overpopulation in the ponds

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sufficient oxygen for the fish in the ponds

water loss in the pond (especially during the hot, dry season)

In the following section, these issues will be addressed with recommendations for operating

a tilapia pond at MDL. The fundamental concern of MdL staff was to determine if an

investment of resources in tilapia farming was a wise business decision.

Old Pond

The existing tilapia pond at Montaña de Luz has a few major issues. According to conversations

with Saul, the existing pond did work successfully; it was able to hold 7 tilapia/m2 at a time. The

pond was active for 6 months; in that time they were able to grow about 300 fish. Tilapia

fingerlings were bought from an outside source. To keep breeding down, about 96% of the fish

were sterilized, giving a low production rate, if any. The tilapia pond was a success in that they

were able to produce a stock of fish for an extended amount of time. However, because tilapia

are harvested at an age of 6 months, MDL would only harvest 600 fish a year at best. During a

change of staff and director, the pond was determined to be too costly for the number of fish

produced and the project was called to a halt.

The design of the pond is the major factor in the high cost of upkeep relative to

production. The pond appears to have been made aesthetically pleasing and not necessarily

designed to meet criteria. The surface area of a tilapia pond is the factor that determines the

possible number of fish. A pond should be about 1 meter deep. The old pond is deeper than is

needed for tilapia to survive. The greater depth actually increases operating costs. With greater

depth, there is more water that must be aerated to keep the oxygen levels of the pond at the

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correct level. A shallow pond needs less aeration because it has more surface area in contact

with the air. The old pond required the staff to keep pumps running longer to make sure the fish

did not die from a lack of oxygen.

The fundamental problem with the old pond is that it could not hold enough fish to be worth the

cost. A possible use of the old pond is discussed in the reproduction section below.

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VI. Future Recommendations

Despite all that has been done, there still remains much that can be done in the future,

although much of that is with the other projects. In regards to the water component, future teams

should check with Vicki and the resident director to be sure that the filtration system is being

sustained, and that the filters are being replaced and installed correctly by Saul. If not, basically

just troubleshoot the issues. There is also room for improvement in some of the past water

team’s projects, perhaps with the septic system or the gravity feed system. Also, the tilapia pond

will have significant water-related components which will undoubtedly need work when that

gets started. Finally, a more effective line of communication should be established between

MdL and OSU so that redundant or unnecessary projects such as the UV system, which does the

same job as chlorinating the water, do not occur, and so that the OSU group is familiar and up to

date with what MdL is doing so that there are no surprises and that MdL can get the maximum

benefit from what OSU is doing. The UV system, installed by a different group, is shown below.

Figure 6: UV Filtration System: Why?

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One of the speakers who came to share information with the class prior to the Honduras

trip was Dr. Jay Martin of the department of Food, Agricultural, and Biological Engineering at

The Ohio State University. His presentation included a section regarding two different types of

biodigesters. His knowledge on the subject surely extends much farther than what was shared

that day and would be an incredible resource for research into biodigesters. The biodigester at

MdL is believed to be completely installed – the biogas just needs to be safely tapped into,

tested, measured, and utilized. It could also be a good idea to design a more efficient system for

retrieving the fertilizer from the output container – currently it appears that in order to retrieve

the compost, someone must place a ladder into the container, climb down, and climb back up

while carrying a large container of fertilizer.

The roof which was put up does not cover the entire garden. One future goal is to assess

how effective the roof is for the gardens at MdL and to examine how well the roof is holding up.

Key points to inquire about include how well the plants are doing now that the shade netting is

up, how well the areas of the netting which come into contact with the middle poles are holding

up, and how well the points connecting the netting to the steel cable are holding up (grommets).

Another goal would be to cover the remainder of the garden if the present roof is deemed

effective and if it is so desired by the MdL staff.

Pond Construction

To make tilapia culture successful at MDL, a new pond (or ponds) would have to be constructed.

Our recommendation is to use the land directly in front of the chicken coop. There is a large

unused area here. Proximity to the garden is a plus as dirty water from a tilapia pond makes

13.6m

8.3m

15.6m

12.6m

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great fertilizer for plants, and proximity to the chicken coop is good because chicken manure is

good for the tilapia pond. A diagram of the current pond is given in Appendix C.

One large pond or two smaller ponds could be constructed in the space. The benefit of using two

ponds is that the harvest of the fish could be broken up into two smaller harvests instead of one

large. If, for example, the large pond had a surface area of 120m2 with a depth of 1m, it could

hold 840 (7 fish/m2). Two ponds of 60m2 could hold 420 fish each. The people at MDL would

have to decide whether they would prefer a 840 fish harvest twice a year or a 420 fish harvest 4

times a year.

Tilapia culture around the world uses a few main types of pond: earthen ponds (requiring clay

based soil with good water retention), concrete ponds, liner ponds, or natural ponds. The soil at

MDL is rocky and therefore very porous and would not hold water well enough. Any new pond

at MDL should be made out of concrete. The construction of the pond is more costly and more

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labor intensive with concrete, but is necessary to retain water. Also, a concrete pond should last

for years.

Reproduction

Once tilapias reach sexual maturity at about 6 months old they reproduce every 6 weeks. They

are generally harvested at 6 months as well, so it is possible that reproduction and overpopulation

may not be problems. Overpopulation can deplete oxygen levels in the pond and kill all the fish

in the pond. Reproduction, if controlled, could also represent a means of replenishing the tilapia

stock without spending the money to buy new fish.

From conversations with Saul we learned that tilapia bought for MDL in the past were sterilized.

One option for replenishing MDL’s supply of young fish therefore would be to buy new

sterilized fish for every new cycle.

Probably the simplest solution to controlling Tilapia population is the use of predator fish known

as guapotes. Guapotes will eat young tilapia but leave the mature fish alone. From Zamorano

we learned that 5 Guapotes per 100m2 of pond is enough to control the Tilapia population.

One way to use the old pond would be to use it for mature fish to reproduce. Several weeks

before a harvest, mature fish could be added to the old pond and allowed to reproduce. By the

time the harvest was made, the young fish would be ready to be moved into the large pond. This

could save several weeks of time and harvests could be made more frequently. The techniques

of reproducing tilapia would require further research to determine the potential. The operating

cost of using the old pond would have to be compared to the cost of buying a new stock of fish.

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It would be recommended to maintain the depth of water in the old pond at 1 meter. This could

be done by simply filling the pond in shallow (which would make it hard to access the fish) or by

filling the pond with rocks and setting a new layer of concrete. Reducing the depth of water will

reduce the operating costs.

Feeding

Feeding tilapia is straight forward. From our research we learned that tilapia will eat almost

anything. A main food source for them is naturally growing algae in the pond water. From

discussions with Saul during the trip, algae grew readily in the old pond. Algae grows more

readily if organic matter is added to the pond such as compost, garden scraps, food scraps, or

chicken manure. It is very important, however, to be careful with the amount of algae in the

pond. Too much algae can result in oxygen depletion in the water and overnight fish kills. In

the day, algae photosynthesize providing oxygen to the pond. When the sun sets, algae respire

and use oxygen in the pond. If there is too much algae, the oxygen can be reduced to dangerous

levels for the fish.

Measuring the algae content of the pond is done by simply measuring the visibility of the water.

You should be able to see about 30cm into the water. A ruler with something bright at the end of

it would work. If you can’t see the end when the ruler is submerged 30cm, there is too much

algae. If you can see all the way to the bottom, there is not enough algae.

At Zamorano, the fish are fed with a fish food concentrate in addition to the naturally occurring

algae in the ponds. The concentrate costs 500 lempira for 6 pounds according to ingeniero

Claudio Castillo, and in 6 months 1000 fish will need 1000 pounds of food. The concentrate

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contains protein to ensure a healthy growth rate for the fish. If the fish don’t receive enough

protein, they will grow more slowly and harvest times will be delayed. The concentrate is a safe

and fool proof way of making sure the tilapia get the nutrition they need. As previously

mentioned, however, tilapia will eat a wide range of food. It may be beneficial to try feeding the

tilapia food scraps or chicken scraps (for example, dried chicken blood from butchering). It is

easy enough to determine if they like it. At normal feeding time, throw some in and if they eat it

they like it. Chicken scraps should contain plenty of protein to keep the fish growing at a fast,

healthy rate.

Our recommendation for feeding the tilapia is as follows:

- Closely monitor the algae growth in the pond ensuring there is a significant amount

available for the fish to eat (this will reduce the amount of store-bought food needed). Using

a ruler with something bright painted on the bottom would be perfect.

- Feed the fish with the store bought concentrate as a supplement to algae. The concentrate

probably represents the most complete source of nutrition to the tilapia.

- Experiment with what else the fish like to eat. If they readily eat chicken scraps or other

available sources of protein, the concentrate can be used less and some money could be

saved.

When feeding the fish, toss in a little food. If they are hungry they will soon come to the top to

eat the floating food. Feed until they stop eating.

Pond Oxygen

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Oxygen content in the pond is critical. Fortunately, tilapia can live on only about 7mg of oxygen

per liter of water. This means that under normal day time conditions, the oxygen produced by

algae and the contact between the surface of the pond and the air incorporates provide enough

oxygen for the fish and no special measures need to be taken to add oxygen to the water. At

night time, because the algae in the pond will start using the pond’s oxygen, oxygen will have to

be added to the pond. This would most likely take the form of a pump that simply re-circulates

the water in the pond. The pump will add operating electrical operating costs. One technique to

limit this cost that we learned from Claudio at Zamorano is to monitor the fish for one full night.

When oxygen in the pond gets to dangerously low levels, the fish will rise to the surface and

gulp the air. When this happens, the time should be noted and the pump turned on until sunrise.

This may result in the pump being run on a timer for 3 or 4 hours a night instead of the entire

night. Care should be taken, however, because as the fish grow their oxygen requirements might

increase and the pump may need to be run for longer periods of time at night.

Adding oxygen to the pond continuously could increase the maximum possible population of

tilapia in the pond. With only night time aeration, the population limit is 5 to 10 tilapia per m3

according to Claudio.

Pond Cleaning

Cleanliness of the pond is important. Claudio told us at Zamorano that the requirement for a

clean pond is to replace 10% of the pond’s water in a week. This water would be very high in

nutrients and perfect for watering the MDL garden. Our recommendation would be to build the

pond or ponds with a drainage valve. The valve could lead to PVC piping that could run from

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the chicken coop over to the garden where it could be attached to a hose used to water the

garden. In this way, wasted water would be minimized.

Cost Analysis

This cost analysis is based on one pond of 65m2 that can hold 455 fish each (7 fish/m3). The

analysis is based on the following calculations and is summarized in a table below. It is

important to keep in mind that there will be a large initial cost to build the ponds and fill them

with water. Furthermore, these calculations are based on many assumptions and information

gathered through 2nd language interviews.

• Cost of fish:

• 27 Lempira per pound (this was the price at U. of Zamorano)

• Fish will be about 1 pound each

• 455 lbs * 27L = 12,285L

• Cost of stocking fish:

• 85 centimos per fish (this was the price at U. of Zamorano)

• 0.85*455 = 386.7 Lempira to stock the pond

• Cost of feeding

• One 6lb bag of feed concentrate is 500L

• Estimate 1/2 bag per week à 7,500L per 6 months

30

• Note: It’s difficult to estimate the amount of food that will be needed. This is

probably the most variable cost. We honestly don’t have a good idea for how

much it will take, but it could become very expensive. The more additional food

sources that can be used (chicken scraps, etc.) the more money can be saved here.

• Cost of pump electricity

• A 20 gallon per minute pump is rated at 1.5A 120V = 180W

• This pump run for, say, 4 hours a day is 0.72 kWH.

• 0.72 kWH at 18 cents per kWH* is about 13 cents to run the pump a day = 23.66

dollars every 6 months. (~425L per pump per 6 months)

*Note: We’re not sure of the price of electricity

Fish Value Stocking Cost Electricity Cost Feeding Cost Net

24,570 772 850 13,000 + 9,948

Table: Cost Analysis for two 65 m2 ponds (in Lempira)

Pond Experiment

The Pond experiment was a test to find the evaporation rate of water from a pond in the

area during the dry season. This was done by using a concrete duck pond that was 156 cm in

diameter and a depth of 46 cm. The pond was filled to 30 cm and was allowed to sit open to the

elements. Every day at the same time the water level was marked at 4 points around the pond in

order to get an average evaporation rate over the whole pond. The data in Appendix A shows the

31

flux of water from the pond per day, Na[cm3/day]. The data from the first day shows a large flux,

this is due partly from the evaporation of water but is more affected by the diffusion of the water

into the concrete lining. This is shown to be true in the following days as the flux comes near a

constant flux. The diffusion of the water is a slight factor to take into account when constructing

the pond. Water will be diffuse into the concrete at first but will then come to equilibrium

between the water and the concrete, so water loss after that point will be solely from evaporation.

The loss of water from evaporation is very small on a day to day basis, which will not be a

problem to overcome. About 10% of the water of the pond should be replaced each week, so

keeping the water at the correct level should not form a problem. Non-chlorinated water should

be used to fill the tilapia pond.

VII. Packing List

List of Necessary Materials

Tape Measure Calculator Journals Writing Utensils Garden (Roof) Materials

o Shade nettingo Grommets/shade clipso Cables, fasteners

Tower Garden Materialso Base material (burlap or similar material)o Ropeo Poles o Soil/gravelo Garden Materials

Tilapia Pond Materials

32

o Materials for detailed documentation Computer/journal Camera Schematics

Water Quality Materialso Testing kit (Chlorine)o Testing kit (Arsenic)o Containers to bring water back for testingo Large container for water (10-15 gallons)

VIII. Useful Spanish Words

water…………………………el aguaagriculture……………………la agriculturaproject………………………..el proyectogarden………………………..el jardinarsenic………………………..el arsenicchlorine………………………clorofilter………………………….filtrarpond…………………………el estanqueroof………………………….el techocompost……………………..el mantillatower………………………..el torresustainable…………………..sostenibleassessment…………………..la evaluacionWhat do you think?................Que te parece?

33

Do you have any questions?...........Tienes preguntas?fish…………………………..el pezsize…………………………..tamañocement………………………el cementodirt/earth…………………..…la tierraquality………………………..la calidadfeed…………………………..alimentar, dar de comer atest………………………..…..probarleave(e.g. documentation, plans,etc)…..dejarinstructions………………..…instrucciones

IX. Team Agreement

34

35

X. References

Emerson, Brock A. The Development of a Project Management Methodology for Peace Corps Mauritania. Michigan Technological University 2006. Pg. 76-101, 115-127.

El-Sayed, Abdel-Fattah M. Tilapia Culture. CAB International. 2006

"How to Compost." Web. 9 Mar 2010. <http://vegweb.com/composting/how-to.shtml>.

Gall, Aimee, Mandy Jensen, Katie Kinstedt, Lisa Reisenauer, and Eric Reynolds. "Assessment of the Drinking Water System and Water Quality at Montaña de Luz and Nueva Esparanza, Honduras." (2008): Web. 9 Mar 2010. <http://ecos.osu.edu/system/files/TeamAguaReport2008.pdf>.

Rush, Vicki. Personal Interview. 24 Feb. 2010.

Water Harvesting and Aquaculture Development Series http://www.ag.auburn.edu/fish/international/waterharvestingpubs.php, Auburn University, Swift, D. R. Aquaculture Training Manual, 1993.

Beveridge M., Brendan, M., Tilapias: Biology and Exploitation. 2000.

Overholt, Larry. Personal Interview. 26 Mar. 2010.

Saul Caceres. Personal Interview. 25 Mar. 2010.

Castillo, Claudio. Personal Interview. 24 Mar. 2010

36

Appendix A: Tilapia Calculations

ho 30 A 782 1.911 104 t 24

H1 mean h1( ) 27.305

dH1 Stdev h1( ) 0.86

Na1ho H1

tA 2.146 103

H2 mean h2( ) 26.273

dH2 Stdev h2( ) 0.704

Na2H1 H2

tA 821.779

dH3 Stdev h3( ) 0.482

Na3H2 H3

tA 720.637

h10

0123

26.6726.98828.57526.988

h20

0123

25.71826.03527.30526.035

h30

0123

25.08224.95626.035

25.4

H3 mean h3( ) 25.368

H4 mean h4( ) 24.447

dH4 Stdev h4( ) 0.635

h40

0123

24.1324.1325.4

24.13

Na4H3 H4

tA 733.28

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Appendix B: Filtration Documentation (posted at MdL)

Instructions for Maintenance of the Filtration System

The filtration system is very important to remove the arsenic from the water, because

arsenic is a dangerous chemical that can cause serious skin problems after years of exposure.

The filtration system is connected to the sink, and contains three cartridges, that need to be

changed every few months. These cartridges need to be in the right order to function properly.

From left to right, the order is the FRC cartridge, then the KCER cartridge, and the CBRST

cartridge on the right. A brief description of these three cartridges can be found below. Also

there is how often you need to change the cartridges: VERY IMPORTANT.

You can order more cartridges by phone (1-800-680-2596), from the internet at

http://www.mrwaterfilter.com/counter-top/mwfct-06.shtml, or directly from the manufacturer on

the internet at http://www.livingwatersway.com. The cartridges are the three on the Mr. Water

page. They are the LW10FRC cartridge, $45.99, the LW10KCER cartridge, $82.69, and the

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LW10CBR/ST cartridge, $73.39. They need to be sent to the MdL office in the U.S. and the

director there can take them by plane to Honduras.

Instrucciones para mantener el sistema de filtracion

Filters

Name FRC KCER CBRST

Picture

Function Removes arsenic and fluorine

Removes small particles and the taste of chlorine

Kills bacteria

Appearance White White and thinWhite and blue with meshing

Time before Replacement Every 4 months Every 6 months Every 4 months

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El sistema de filtracion es muy importante para limpiar el agua porque quita el arsenio

del agua, que es un quimico peligroso que despues de algunos anos puede causar muchos

problemas graves del piel. Este sistema de filtracion consiste en el sistema que se conecta al

agua, y de los tres cartuchos, que necesitan ser recambiados despues de algunos meses. Estos

cartuchos necesitan estar en el orden correcto para funcionar bien. De la izquierda a la derecha,

el orden es el cartucho FRC, el cartucho KCER, y el por la derecha el cartucho CBRST. Una

descripcion breve de estos tres cartuchos esta abajo. Tambien hay cuando se necesita recambiar

los cartuchos: MUY IMPORTANTE.

Se puede pedir otros cartuchos por telefono (1-800-680-2596), del sitio de red

http://www.mrwaterfilter.com/counter-top/mwfct-06.shtml, o directamente del proveedor del

sitio de red http://www.livingwatersway.com. Los que se necesita son los tres que estan en la

primera pagina de red. Son el LW10FRC por $45.99, el LW10KCER por $82.69, y el

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LW10CBR/ST por $73.39. Se necesita mandarlos a la oficina de Montana de Luz en los

E.E.U.U. y el director alli puede tomarlos por avion a Montana de Luz.

Filtros

Nombre FRC KCER CBRST

Foto

Función Quita arsénico y floro

Quita partículas pequeñas (metálicos malos) y el sabor de cloro

Mata las bacterias

Apariencia Blanco Delgado y blancoBlanco y azul con

malla

Vida Útil Cada 4 meses Cada 6 meses Cada 4 meses

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Appendix C: Measurements (Tilapia Pond and Garden)

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