I'm a high school biololgy teacher who has had every animal imaginable in my classroom. I'm done with animals. Love them, but they are too much trouble. I want to set up a plant aquarium. Mainly Elodea and possibly other freshwater plants. We use Elodea quite a bit in our Biology labs. I've read just about everything out there on how to set up the aquarium - light, CO2
, temp, pH and substrate. I'm having conflicting reports about the substrate. I want something that the plants can take root in. I have very little money, so I don't have the cash to by the eco-complete or fluorite substrate. I've read about peat (which I already have), clay (read stuff on the plain kitty litter and also pottery clay), along with sand or small gravel (I already have the sand too.) Does anyone have any sound advice on how to set up the substrate for a planted freshwater aquarium? Again, mainly Elodea.