Haha, I understand. When I was a kid I had a pond tank. I think I've talked about this thing. It was all pond fish from the one down the road from my parents neighborhood. Plants, fish, bugs, frogs, crawfish, sirens... ever seen a siren? Really cool looking, take the front half of an axolotl and stick the back half of an eel on it.
Anyway, it ran on an under gravel filter driven by an air pump and tap water with no conditioner. I probably never did a water change until the tank water was green as pea soup, then I pulled it all out in about a 90% WC, with tap water. One thing I never did was remove the under gravel filter until I took the tank down. The thing is, all the fish I had thrived. I learned how to observe different fish and their behaviors in that tank.
Now I wanna set up another pond tank... hahaha. I do have that empty 40b...
