I got this at Walmart it's actually for food storage and comes with a lid (which I won't use since it's pretty airtight). I had bought another 5 gallon aquarium also $10.00 but decided with the frequent water changes this would be good. The 15 watt heat is a flat heater not adjustable. I don't think I want much gravel in the tank (this could change if it's best) I am worried this is too much for two gallons since it heats 5gallons.
I also am wondering if the fish could burn itself if it's not buried. I am treating for fin rot. This is it:
If you want this jar for temporary housing of a bettai t's in the houseware section. This is the specifics and a picture: