Backyard Aquaponics
A place to discuss aquaponics

After several test/hobby systems, I have figured out a few things that will work here and some that won't. My Rehab Center project has gone so well and is producing so much, that I have decided to see what it would take to make a system that would actually produce a steady income for a family.

The minimum wage for a general worker in this area is about $5.00 per day or about $120.00 per month. Ther is talk of the Minimum Wage rising to about $200 per month so I want to base things on that figure. I figure that if I can design a system that will produce a minimum of net income in the $8-10 range then it will be something that should generate a fair bit of interest among the locals especially if I can keep the start up costs to a manageable level.

Tomatoes go for about $0.25 each and Cucs for the same. A head of lettuce will bring about $0.40 and green beans bring $0.50 a pound. Tilapia will bring about $1.50 per pound scaled and cleaned. Green peppers three for a quarter.

All the above mentioned veggies I have found do very well here so the goal would be to plan a system and manage it in a way that there will be a constant flow of produce that would at those prices add up to between $8.00 -$10.00 per day, after expenses.

The expenses would be the pay back of the initial investment, and ongoing costs such as electricity, marketing costs and seeds. I am not including labor because that would be the profit, their labor.

I have designed a system that is a 700 gallon system for the fish, and 1400 gallons of grow bed using lava rock or pumice which we can get locally. Because power outages can occur and last about 4 hours maximum, I would not want to stock at maximum densities but pretty close to it. I really don't want to get into the solar thing because it is not efficient and it is very expensive to get here and must be imported.

So, the tank will be dug into the ground, a long narrow tank so fish herding is more efficient. The sides and bottom of the tank will be ferro cement.

The grow beds will also be ferro cement and hold between 130 gallons and 300 gallons, depending on what will be growing in them. Lettuce beds will be large while tomato beds will be 1 foot wide, 1 foot deep, and 8 feet long. Each tomato bed will hold 16 determinate heirloom tomato plants or cucumbers. All other veggies will have beds designed specifically for them to maximize space and materials. I may even have a few beds that are simply full of water for floating rafts similar to what the University of the Virgin Islands does.

The first system will be built to sustain a family this way and then it can be expanded if the opportunity arises to grow.

Any thoughts are welcome. No pics are available yet since my sketchup skills are non existent and I am just beginning the molds for the ferro cement tanks. I will definately document the whole process and post results here.

My goal is to produce a system for between $250.00 to $450.00. I am not sure that will be possible but that is what I am shooting for.

well done Dave, I hope it all works out for you and your potential APer's

Hi mate...

I understand that some aid agencies are able to provide low interest loans for small scale domestic and village scale projects that reduce poverty and put food on the table.

It may be worth talking to the Food and Agriculture Organisation in Rome to see exactly which people to talk to. (I will pm you details of contacts who may be able to advise on all types of aspects.)

That sounds wonderful, DT!!

Very exciting DT, sounds like a plan!

Good work DT, all da best eh....
Could always setup a plan for backpackers to come work on it and stay/eat fer free lol
always wanted to go to El Salvador!

nice one DT i am right behind ya with mines as well

The way volunteer work works here is that you can fly in, walk in, drive in, and work. Don't forget to bring money for food. Kind of defeats the purpose if I have to spend money destined for the poor for other reasons. Having said that, volunteers are always welcome. I can provide a free bed.

With my goal to produce an income of $10.00 per day, I am coming tot he conclusion that it will be best to concentrate on one or two crops that produce well and the primary one is tomatoes. Cucumbers would be the other.

After talking with the chief Techie from Crop King, we worked out the following scenario.

We will have an in ground fishtank hoding about 600 Gallons of water. This will be a long tank about 2 feet wide or 600 mm. This will make it easy to herd the fish to one end for harvest and to put screened partitions in to classify fish.

At ground level, we will have 11 grow beds that are 12 inches wide by 12 inches deep by 8 feet long. (300mmx300mmx2.8m) Each growbed will hold 18 indeterminate tomato plants. We calculate each plant to produce about 25 lbs during a 7 month lifespan.

The tank will produce about 250 - 300 lbs of fish in the same 7-8 months. This is roughly 15 lbs of veggies for each pound of fish produced. We calculate we will use about 450 lbs of fish food during that time for a total of $65.00. It will cost about $35.00 in energy for the pump during that time.

With the use of ferro cement for the tank and grow beds and drainage pvc for the plumbing, we hope to bring the initial cost to $400.00 or less to the individual. My hope is to provide it to them finance over 12 months so we don't create unhealthy dependencies and so there is a higher commitment to making the system perform as it was intended.

Anyone see any holes in the thought process?

Sounds pretty good to me DT.....

Are Crop King coming onboard with any assistance other than advice?

This is a pretty pathetic rendition in Sketchup of what it will look like but you get the idea. The GBs can be configured to match the terrain and more can be added or some subracted to accommodate space/budget.

Good work DT!!
Could you create a raft system that doubles as a header tank?
I was thinking that it could be good to have a constant DO flow to your fish during power outage and perhaps this could be done manualy by opening a valve to shoot(small nozzle) water from, to your Fish tank.
(can use a bike/other manual air pump and airstone to keep DO up in a HSM).
Keep up the good work!
I like the idea of franchises...
that way you set it up and supply the system, help to monitor/teach.
You would have to be good enough to prove production and then negotiate your return on the system (produce=payment).
That would be food production at close to labor costs.

That is something to look into.... at the moment I am more leaning to the kids using a 5 gallon bucket to add watter to a grow bed until the siphon kicks in.

That is what I do with my system. For the most part outages are seldom more than 4 hours since the Electric company must reimburse $10,000 per hour to customers if they go over that length of time.

That is one reason I am keeping stocking rates below what can be to keep from having too many disasters.

Questions for you to ponder....

Are tomatoes and cukes the highest income-producer? Here, I would say basil. Do you have problems with cukes getting 'wilt' down there. I lose mine pretty reliably every August to wilt.

How will you finance the loans to new owners? Do you have seed money to start, and then low-interest loan re-payments help keep it going? How will you provide tech support to folks to help solve disease or pump failures? Do current owners have the obligation to help build future systems or otherwise 'pay it forward'?

Good questions. To start out with, Tomatoes are a staple in nearly every food in El Salvador and it is fairly profitable. a pound of tomatoes can go for as high as $.70 and as low as .40. There is never any problem getting rid of tomatoes.

Cukes are very used here as well and there are varieties that do well here regardless of the heat. The start up monies should not be real hard to get however we have not crossed that bridge as of yet. I should be able to raise about 5000 capital to start with and I will be funding the model system.

For Technical support I am trying to work with a local NGO to see if they want to share the load and use one of their agronomists part time for the project. The Salvador department of fisheries is real interested in seeing how they can encourage the production of Tilapia and freshwater shrimp across the country so and they are funded by the government of Taiwan so there may be some technical support from them and possibly some funding.

Of course at the core of the plan we want to teach people to teach others.

Thanks for your questions, they are helping me work things out in my mind. Tomorrow I begin putting cement on the molds for the growbeds. I will post pictures of the progress. I have already planted the seeds so plants will be transplanting height when the grow beds are ready.

My Conversation with the Tech guy from Crop King helped me with learning how to grow indeterminants. Real good ideas on potassium and phosphorus, iron, and foliar sprays, compost teas.

More later!