Backyard Aquaponics
A place to discuss aquaponics

Chappo will probably tell you that not feeding pellets for most of the tilapia diet will probably mean much slowed growth, he does mention that certain plants (like Moringa) can replace say 30% of the diet but more than that and the growth rate is affected. Granted, his tilapia operation is definitely commercial and their primary goal is to at least break even but hopefully make a profit. Worms and BSF larva make nice additions to their diet but A diet primarily made up of BSF and worms would likely cause health problems for the tilapia (something to do with too much fat causing problems for the tilapia's liver.)

I have found that our tilapia really like eating the leaves off sweet potato vines. This is very convenient for us in the summer as sweet potatoes and their vines will take over the yard if we don't keep cutting them off when they run where we don't want them. During warm weather our 100 tilapia would happily clean the leaves off of 6-12 feet of vines each day in addition to their pellet feed. They will eat moringa leaves a little bit which are even better for them than the sweet potato leaves. They love lettuce or other tender greens that we usually eat but they don't get too much of those since we eat them.

Just a note about duckweed culture. Many people have found that you can't produce enough duckweed to feed your fish unless you devote a rather large surface area to producing it and make a point of drying a % of it on a regular basis.

If you are not needing a certain amount of fish to feed people at some set interval, then it is probably ok if the fish are not being grown out as fast as the commercial producers do it. Tilapia that grow slower and eat a more varied diet are probably healthier for the people who eat them.

Do keep in mind that when the fish are young/small, they really need a pretty high protein feed. The babies will eat each other if they can and are not being fed enough protein. Remember that even though people talk about how tilapia can be feed as herbivores, they actually do eat other creatures all the time. Most of those other creatures are microscopic and we therefore tend to forget them but they are very important to the wild tilapia diet. Tilapia will also eat bugs, worms, BSF larva and the young ones will eat the even smaller young ones.

Feed is the biggest expense and challenge for a commercial fish farm and there are many of us here on the forum thinking about alternative feed sources. Some people cook up their own fish feed. To your duckweed and worm culture feed sources, you might look into algae culture (I'm not really talking about growing algae directly in with the fish as this can make balancing the system tricky) to grow feed for the fish as well as possibly food for the people. Moringa is another good food source for people as well as fish. Sweet Potatoes are really good for people and as mentioned, the leaves are a nice supplement to the fish diet. Sweet potato leaves are also fine for people to eat, I especially like the vine tips and young leaves added to stir fries and salads.

The kids could hunt for bugs now and again to supplement protein.

Fair go Johnnie.... feed them real food... poor kids...

God bless you for what you guys are doing. I think this is why aquaponics needs to be done. Food is getting too expensive and here in the US its all modified and engineered to keep the price "reasonable" but at what cost to the consumer. What you guys are doing for these kids is going to change their life. They'll be fed and learn what it means to take care of themselves and to take care of something that people they love need. That's the type of responsibility most people need to learn in regards to their food.

I was just wondering have you thought about using wood like 2"x12" (sorry don't know conversion to metric) for building the fish pond walls. By using wood and liners you could build alot more of what you need. I built an 8'x8'x3'high pond with 2x12's, 2x4's and liner and it's holding up really well. Here in Hawaii it cost me about $180 for the liner (EPDM 15'x15') and $200 for the wood. The ponds about 1400 gallons. I did this cause it's impossible to find large ponds here. I haven't built a grow bed yet but I am planning to build my first one in a month or so. Gonna use 2x12x24' long pieces with liner and was thinking of a raft system (styrofoam) for leafy vegetables. You could build grow beds using the same technique I'd assume.

I built grow beds using wood and liner.

I find a good shape for growbeds using liner is about 3' wide and 1' deep by however long is reasonable. This is because a 5' 6" wide roll of liner is a standard width and therefore relatively cheap compared to getting a wider roll. My monster bed is right on the ground. with a 2 X 6 frame around the top and stakes pounded into the ground to hole the frame from bowing out too much. Not very elegant but it worked.

Liner for grow beds should always be really heavy tough stuff or you risk holes and leaking. I like the EPDM stuff as it is really tough and pretty easy to fold.

HHa ha ...
I guess you know I was meaning feed the fish with the bugs not the little kids!

Although I have eaten fried locust whilst in NE Thailand.

gonna have to go with the original tanks,any other option does not make it feasible.what do you guys think about this design and will it work

yep. why the midde connects? Just using the bottom ones will be fne.

SA Aqua,
Let me know how the organizational part goes. I too am starting an organization (tentitvely- "Sustainable Missions") to help people by utilizing sustainable technology.

Our first project is to build a large (non-commercial) AP system for an orphange in Nicaragua. The orphanage director wants us to teach some of her older kids how to maintain the system to give them some cutting edge job skills. If the build goes well she wants us to help some others she knows of in some other countries, including Africa.

We will prototype our prototype on some property a local church is going to let us use. Hopefully begin soon.

Anyway, we're in Pensacola, FL, USA. Let me know how it goes for you.

Blessings,
Tony