Backyard Aquaponics
A place to discuss aquaponics

After being marginally successful at AP with two systems under my belt and a third one begining, I decided to help others get started doing this not as a hobby but as a way of supplying protein and fresh veggies to local residents.

The area in which I live in El Salvador, is economically depressed for reason's I won't get into here but they all have access to electricity, volcanic lava, pumice, and Tilapia fingerlings. Several people have looked at my systems and feel they want to do their own.

I found a pump vendor in the U.S. called Fountain Mountain. I purchased a lot of 12 pumps300 gph for a 18.60 each including shipping. I received them yesterday and they look to be nice pumps, not much really that can go wrong that can't be easily fixed. 25 watt units. I ordered some spare impellers so I should be set.

I found a place in San Salvador that sells PVC pond liner for $4.00 US per square meter. Since it is PVC, it can be trimmed and glued using normal PVC pipe cement. This way I can dig holes or make boxes in any shape or siz and fit it with this liner. It can be used for tanks and growbeds. This place is also a good source for drip irrigation fittings so I should have all I need to begin at least 12 systems in the community.

I was also able to find tilapia pellets for $0.13 US per pound or a 100 pound sack (45.35 kilos) for $13.00 US. Of course we can grow some of the food for tilapia as well.

My thought is to use a tank that is 2 meters long, 800 mm high by 1 meter wide. (1600 liters, 422 gallons) I have figured for 2- 1200 liter growbeds.

Including the pump, plastic and pipe, the cost would be about $200.00. This would not include what the liner goes in. In most cases this would involve digging a hole in the ground for the tank, and using the dirt to create a growbed that would also be lined. However, cement block may be needed or wood in some circumstances. I feel that at most the total setup cost would be $300.00.

Most people here can not come up with that kind of money so I will be looking for system sponsorships to cover about half the cost of the system and they can borrow 1/2 the remaining amount at a low interest. Their total out-of-pocket expense would be about $75.00. This size system would allow enough space to grow veggies and fish to sell as well as consume.

Any thoughts on this? I would love to get feedback on whether or not this is a doable project before I put a lot of time and expense into this. Right now all I have in it is the price of 12 pumps.

That's wonderful, DT. Start everyone up with a nice bucket of seasoned lava rock from your system. It's like Amish Friendship bread (I think that's the name.) You have a starter culture (like sourdough), bake with some, save some for yourself, and pass some on to a friend.

I think the hardest thing is the nitrogen cycle. If you can use some method of giving them fish in installments, maybe you can avoid the new-system setup issues. (Start them with maybe 2 fish, then build up. Or maybe really little fry. Not that you know where to find those. ) Even for someone experienced, suddenly dropping 100 fish into a system causes challenges.

Keep us posted!

DT your motives alone are a good enough reason to give it a go...

What about the local civic and business leaders.... would they be prepared to come on board with sponsership??

Or is the gap between social levels too great there in El Salvador for things like that to happen?

There's an organization called Heifer International http://www.heifer.org/site/c.edJRKQNiFi ... PgodBHWC3g

Their concept is that they give people pregnant female livestock, stud services, and training with the understanding that the first female offspring that is produced will be given freely to another family in need. That family does the same, and so on through the community. Cows, llamas, water buffalo, whatever it happens to be. People can start to generate cash from sales of milk or wool as well as feed their family.

Maybe you can set up a similar cascading idea, where the first families to benefit help the next ones. Whether that's with labor to build the system, or the gift of a pump and fingerlings, or what. Figure out what might work given the circumstance.

Or, maybe Heifer International would like to sponsor you or something. Hmmmm....

Great and noble idea DT!
Maybe you could get the systems started on your lot, then transfer everything to their lot once it is cycled, etc? Sort of a moving day ceremony or whatnot. Then you get the next one going and part that one out?

Good ideas. However if I use liners, it might be a bit of a problem starting the system on my lot and transferring.

My main question is whether the size of the system seems reasonable. Not too big for someone to handle but big enough that it would be more than a hobby. I want it to do some good not just be added to the pile of failed projects in Third World countries.

I was hoping for someone to weigh in on the materials and costs of the systems as well. I know Travis does work with blue barrels but they are not real accessible here and when you find them they are $30.00 US. There are more fittings involved so costs are a bit higher.

I may be surprised but I don't feel that sponsorships will be that much of a problem. The question is, will this have the potential to help the singel family if taken care of.

2400 liters of beds would support a fish load of 150 pounds (68kg), theoretically. (Using the worst of 1 pound of fish: 2 gallons of water : 4 gallons of filter media. Your limiting factor is the bed size since you are at 1.5:1 -- less than 2:1 bed:tank). (You may also want to watch pump size. I'm think you may want to use one pump per bed (2 per system) to get high enough turnover to support good fishload. I'm re-plumbing right now to try for turnover of 3x per hour.)

My limiting factor is also my bed size, but I am at 1.2:1. Your proposed system is 4 times the size of mine, as measured by the limiting factor of bedsize. Using staggered batching, and eating tilapia between 300g and 600g (.66 pounds - 1.2 pounds), I projected that I could harvest 88 pounds (40kg) of fish a year. Dressed out, count 44 pounds of protein. So your proposed system could produce 4 times that: 352 pounds of fish, or 176 pounds of protein in a year. A family of 2 adults and 3 children might eat a pound at a meal, so you just provided over 3 meals a week with protein. Not so shabby.

At this point, we haven't even discussed the vegetables and herbs. I've heard various ratios of how many pounds of veg is produced per pound of fish produced, and that's going to depend a lot on whether the system is skewed towards fish or veg. (At the moment I can't figure out which way we skew.) One of the ratios I remember was that the system in question was producing 8 pounds of veg for every pound of fish. I think the Spereano system was producing a lot more than that. So if you are harvesting 6-7 pounds of fish each week, that should mean 50 pounds of veg each week, too. That sounds a bit unbelieveable, and someone with a more mature system should chime in here.

Now all of the numbers above assume year-round warm temperatures, and a carefully managed system. Also, let me insert the standard disclaimer that this is based on my research, but given that my system is only a few months old, I haven't actually achieved any of this.

So bottom line -- I think it is a good sized system to make a difference in a family's life, and to be manageable. Go for it.

Wow Janet, thanks. Even if we only met half of those numbers, it would be a self sustaining number. Thanks for the info. I also am looking around to see what can be done. We cetainly have year around warm temps, 6 months rain, 6 months dry. I still have a few more things to work out but thanks for the encouragement.

DT ..

U are inspirational.

I can't wait to see the results.

Thanks, neither can I.

Dt,
what's the latest on this?

By the way, my little brother lived for a short while on the side of "lago cuaotepeque" (spelling?) just outside of San Salvador a ways. I visted there and could have stayed, I thruroughly enjoyed it.

DT, there is another organization called "Kiva". You can access them on the internet. They are into direct micro loans for persons in developing and third world countries. It sounds like to me that some of your end users would be qualifiable for the program provided they can produce enough money from sales to repay thier loans.

Heifer International is more into supplying animals, materials and training. They would also be worth contacting about program participation.

Many years ago the United Methodist Church was supplying two wheeled tractors to farmers of developing countries. You can contact them and see if they are still involved in this or any other activities that could be of help. (The tractors are meant to be used for both cultivation and transporting goods from the farm to nearby markets.)

Kevin

DTHawk,

You and I wrote back and forth in here a few months ago. I live over in Belize, a short TACA flight from San Salvador.

I'd like to visit you in September to see what you are doing. I am developing a pond based community aquaculture project right now here in Belize, and am considering aquaponic grow beds for biological filtering and aeration.

Any photos of what you are working on?

Paz,

Christopher