I'm no expert by any stretch of the imagination hehehe but I do have 22 tanks down stairs in the garage with no help from a chiller during summer or a heater over winter. Agree with everything inkevnito said ...also netty_3164 especially about the new layout of the forum lmao as i try to navigate. I read here once a great saying (think is was Donny AOA .. please excuse if I'm wrong) Its not keeping fish, but rather keeping water. The fish take care of themselves with the right quality. Sounds like you understand how to do this from your past experience... I would add though that I run mostly bare bottom tanks meaning no subtrate. Gold fish can be messy . They do have anubias on wood and duckweed though so not barren. Just keeps my water easier.