Thanks for the help. It does seem like there are very few fish that are good in coldwater tanks. I've been reading that several kinds of tetras and danios can be good in temperatures as low as the mid 60s, but my tank definitely gets colder than that. I guess cloud mountain minnows would be good.
As far as tank size...I don't mean to beat a dead horse or whatever but saying that loaches need a minimum of 30 gallons isn't necessarily true. My loaches are doing great in their tank. You act like they can't live in anything smaller than a 30 gallon tank, but do you even have any loaches? I don't mean to sound like a creep but repeating what you read on a website about loaches doesn't make it a fact, plus its annoying to tell someone that they need a bigger tank for their fish when they clearly weren't asking about that. My fish are each under 5 inches long. I do know that if my fish got to be 10 inches long, which is pretty unlikely from what I've seen and read, I will have to put them in an appropriately larger tank. But I was just asking about other species of coldwater fish. That's just my opinion and I've given this speech to more than one other person on this site.