Backyard Aquaponics
A place to discuss aquaponics

ok so i'm moving house and while cleaning and purging all the stuff we don't need ie.2 kids =1000s of toys,we decide to go give it to a small orphanage that i drive past everyday.i'm a big guy and what i saw there brought me to tears for the first time in many years.this place receives no government assistance because most of the kids are white(so much for the rainbow nation)all assistance is by private donations.
enter the "400"group that im starting.i have a large group of friends that own their own businesses.each of us, 20 in all will donate R4OO(sorry don't know the conversion rate)every three months to a sustainable project to those who need it the most.our first project will be a AP system,that might make them more self sufficient and more importantantly educate them.this is where i hope you guys can help with some tech advice.tis is what I've got so far.how many grow beds can i have?how many tilapia can i stock?thanks guys

how deep is the fish tank? the grow beds look like a good size, but they may need to be shaded to help reduce water heating issues

Great work

tanks are 400 deep,the system will be in a small green house

Great idea... those growbeds look perfect....

I make them about 330L.... so one per tank would be a 1:1 ratio....

You could push to the 2:1 ratio.... (2 growbeds/tank) ... but the fish tank might not be deep enough and large enough in volume to increase the density too much...

Still, with Tilapia.... you might get away with 4kg/100L.... => 12Kg per tank.... about 25 plate sized fish....

Would need to provide lots of oxygenation and tank turnover (flow rate) though....

Considering the environment it is going onto, the lower density is probably the best option.

1 tank per bed, shaded from direct sun (hessian?) will work well.

400mm deep is pushing it for edible sized fish in any large sort of quantity.

i got 3 of these tanks, would it be a good idea to join the tanks with a large diameter pvc pipe.15 kids at this place

For 330l tanks youll get away with 25 or 32 mm pipe.

I would join them for stability. Takes longer for things to go wrong with 1000l of water versus 300 odd.

You might also think about using two of those tanks CHIFT PIST (constant height in fish tank pump in sump tank) style and use the third tank as the sump, or better yet, find yet another item to use as a sump. Then the fish tanks won't fluctuate in level so much and the pump can be in cleaner sump water after the grow beds.

When people say you can get away with smaller pipes for connecting tanks together, I agree that you can, but larger pipes for such things are usually a good idea. Before connecting everything together, do lots of reading to figure out what layout will really work best for the situation.

Also, you have a few separate tanks there, it might be worth thinking about ways that one might be kept isolated with a grow bed for quarantine purposes, that way a new batch of fish can be kept separate for several weeks before introducing into the rest of the system. Just in case ya get a sick batch, you don't want to infect the rest of the fish. It also makes it easier to heavily salt to deal with an illness if you are only doing it to part of the system but that requires being able to isolate and having a second pump, though it might be smaller.

How will they afford to run the system? (Electricity, fish feed, testing, pump replacement parts etc.) Who will maintain and watch over the system? Is there someone already there very keen on the idea? Who will teach them and go out there every day to check on things during initial cycling? Do they have internet access to use to ask for help and advice once they are operating on their own? (I know you have probably already answered many of these but thought I should throw them out there in case some got missed. I'm sure I missed some important bits too.)

Good Luck with the project!

Where is the orphanage SAA?

You have no other alternatives for a FT? Thats going to be really hard to keep stable.

They almost look like two halves (the one has a rim and the other maybe doesn't?), can they be bolted together and sealed with silicone or some other kind of gaskety thing like rubber liner? That would be 600L. Then make some cutouts in the top to get to the fish...

Hello people

The FT is 16" deep, in my terms, it slopes outwards. The water level is likely to be sitting 3" below the top. Thats an effective depth of 13". Yes you could keep goldies in that but tilapia to plate size?
Its a worthwhile project, lets try to think in practical rather than theoretical technical possibilities.

Yep, I tend to agree... 400mm is just too shallow to be of use for any real number, or size, of fish...

Tilapia can be grown under almost "abusive" conditions... but unless the tanks were Chift Pist and maintained a constant height... then it's probably noy even possible with Tilapia....

Perhaps you could get some of those mesh tanks that seem so readily available in SA...

Forgot to add.... if you source some more practical tanks... you can always use the current "ones" as growbeds.... say for tomatoes or fruit trees...

TCLynx
the running costs will be as follows,we are looking at either solar or wind power to supplement the power costs,tilapia rendali will be stocked in the tank-these fish can be totally herbivorous,so a duck weed culture will be set up for food.to supplement this two earthworm trenches will be set up.the orphanage is producing enough waste from their current food intake to support this.i will personally supervise the system daily as i own my own business and my times are flexible.
RupertofOZ
gonna have to go that way i think,maybe sink it a little with a safety net over it,want the kids to see the fish. using the original tanks as growbeds is an awesome idea.
cyara the place is in durban north