The water measured is pretty close to 3 full gallons I think the bowl description put 3 gallons as how much liquid it can hold since it was not intended for fish but for punch.
It's in a really hot room in our home now that's 76 and it's freezing outside. We have to keep our home warmer for medical reasons. So it'll probably be 78-80 in summer.
I have substrate coming in, that - snails and moss do great for water cleansing. I change the water weekly and at that point it still looks clean.
This is the first new home where they made bubble nests on the first day so I know they like it. Lots more betta dancing going on.