I have a 250 gallon pond setup in my unheated garage. Temperature gets down to the low 30's in the winter so I need some coldwater fish. The temperature in the summer outside is in the 90's so I figure the water is in the 80's. What fish would you suggest. I may do a brown bullhead and some bluegill. Is there an kind of loach that would work. I open to anything. Would a weather loach work?