Mini ecological system fish tank (I don't know how to call it)?

Question

I remember back about 5 or 6 years (or even more) ago when I saw a Popular Mechanics for Kids episode, in which Charlie explains how to make a mini ecological fish tank. Which means, you don't have to feed the fish, don't have to add oxygen filters etc. You just put inside the tank some plant which generate oxygen, some snails which eats the plant and the snails' sh*t (sorry but I can't find any other way of expression, my english is way too bad) becomes food for the fish. I don't remember the details very much. So can anyone of you guys show me how?

Answer 1

I remember those - I also know a lot of people whose fish died in them! It seemed like a good idea at the time, but they didn't support the fish living in them beyond a few months. Turns out, the fish don't eat the snail sh*t, they ate the plants, which cut off the oxygen, which killed the ecosystems.

Here's a basic system without fish - this will work a little better, but is still not perpetual! http://www.beachworld.co.uk/biosphere.htm You could make one of these with a fish bowl and cover the opening with plastic wrap. Or use a 2 - liter bottle with a cap. Good luck!

Answer 2

it is known as a "Symbiotic Relationship"-----you still have to feed the fish-----but the fish eat the algae the plants produce-- plants utilize the fish waste and absorb the carbon dioxide that is exhaled by the fish-----and in turn give off oxygen---this sounds great on paper but cannot be done completely in a small tank--but can sure make a beautiful and healthy environment for the fish