Ok, so here is our setup. We are going to have a 10g divided into 4 sections with a fish in each one. These will be fish 1, fish 2, fish 3, and fish 4. We will also have 3 types of food we will test. Flake, crisps, and pellets. F1 will get flake, F2 will get crisps, F3 will get pellets and F4 will get a mix. No substrate and each fish will get its own DIY sponge filter. Does this setup sound good? Also, I have a heater, but how would I place it in the tank so that all the fish get warmed equally.