Backyard Aquaponics
A place to discuss aquaponics

I really need some help here guys.i've been offered a 1meter cubed 19mm thickness glass aquarium for free.Could i use this for my future AP project if I build some kind of protection around it,not for insulation as I live in a tropical area.How do I work out the amount of water needed for this tank and how big should the grow beds be.Gonna be using Tilapia rendalli fingerlings of between 30 - 75grams,how many should I start out with?

I don't see any reason why it wouldn't work.

1 cm^3 = 1 mL.

1 m^3 = 100*100*100 cm^3 = 1,000,000 cm^3 = 1,000,000 mL = 1,000 L

1:2 FT:GB; 2,000 L of grow bed

Thanks T,how many fish would I put in this system?

General rule of thumb seems to be 1kg of fish for every 50 L of *grow bed* volume. So 2,000 / 50 = 400 kg of fish.

So how many fish that is depends on the type and size of your fish. If you harvest at 1.5 kg per fish, then that would mean approx 250 fish as a *maximum*.

Tamo, 2000/50=40kg, not 400kg. At 1,5kg per fish, that would mean about 40/1.5=26 fish; I don't think tilapia grow to 1,5kg in just 1000L though. Most people harvest them at 500g, so that would mean 40/0.5=80 fish.



Anyways, hello and welcome, Kynan!


That aquarium sounds perfect for AP!

The amount of fish you can have in your system depends mostly on the total growbed volume filled with gravel or other media that you have, because the growbed acts as a filter for the fish. The absolute maximum is 3kg of fish per 100L of growbed, but this is in a mature system where everything is perfect (which is almost never the case). Usually it's not more than 2kg per 100L (like Tamo said).

The optimum growbed/tank ratio is about twice as much growbed volume as fish tank volume, so you can have about 2000L of growbed. This is about the same as 10 bathtubs. You don't actually need this much, though, you can also start out with only 200L of growbed. Keep in mind though that with less growbed volume you can support less fish.

Using the above, you can have an absolute maximum of 60kg of fish if you have 2000L of growbed volume (or 6kg if you have 200L). A plate-size tilapia is about 500g, so that means that you can have an absolute maximum of 120 big fish in your system if you have 2000L of growbed volume.

Even though your fish start out much smaller than 500g, I wouldn't advice putting any more than 100 of them in your system. In fact, I advice you to start small with only about 10, maybe 20 fish. It's a learning curve, and you wouldn't want to find all your fish dead at a certain point.

In any case, good luck! Please keep us informed of your progress.

2nd'ed! Mental algebra strikes again

Thanks guys.I've got quite alot of variables to work out before starting with this project.Here in South Africa we are not able to get all the products ect to start imediatly with this kind of project(AP is basically uheard of here),got some natural wildlife(monkeys,kingfishers,herons ect) to deal with.So thanks for your help and I will be picking your brains again

Kynan, Aquamad has a 1000L glass tank too
http://backyardaquaponics.com/forum/vie ... 6699#76699
http://backyardaquaponics.com/forum/vie ... 2894#72894
http://backyardaquaponics.com/forum/vie ... 0631#70631

Kynan, a couple of links you might be interested in ....

http://www.aquaafrica.co.za/

http://www.aquaponicsafrica.co.za/the%20operation.html

And there was a member Mike Evans that was active for a while...

http://backyardaquaponics.com/forum/pro ... file&u=256