I'm am thinking of making my closet my fish room - it's almost as big as a walk in, not quite deep enough. But it will work great. It stays pretty warm in there and there's lighting.
I have a thermometer in there to see if the air temp would be suitable - so far last night to now it's stayed about 76, which would mean water temp would probably be 72-74. I am anticipating the air to get to 80-82 or higher even, which would put the water around 76-78 at the height of the afternoon.
Since these temps are a little on the cooler side, but gets to ideal in the afternoon, would I be ok having my fish/fry in there? I could run heaters to the spawning tanks for sure, but the rest would be heated by the air in the closet.