I can get a heater for my 3 gallon tank and try to find a small filter for it. I could put it in my room. When cleaning out my son's room we took out a wooden stand with 3 shelves on it, just have to reinforce it a little so it is more sturdy, which wouldn't take too much to do. I am thinking about it. I would be able to get 3 10 gallons or more smaller tanks on their if it is reinforced. I think I have some wood somewhere in the house that I can use or maybe go and see if the hardware store has small left over pieces that would be cheap to get. It will take awhile to find the tanks I want to buy and fix up the stand but maybe eventually I will get back into bettas or maybe small tetras, not sure yet. When I do I will have pictures, just don't expect them until the winter or maybe early next year. These would go in my bedroom that is why I would need heaters for the tanks, it gets cool in there in the winter and when it is raining. I don't mind the coolness but the fish wouldn't like it.

Good luck. Sounds like a neat idea.

Good luck with your project - it sounds great to have more Bettas. I agree though, make sure that unit is really strong and sturdy