This morning my tank got extremely cold. Like, down to 55-60 degrees! Obviously, way to cold for my fish. So, my question is can I turn on the heater in the tank with a hillstream loach in it? Or will it burn the little guy? I usually don't have to use it, the tank just tends to stay warm, even in winter. So, is it safe? Should I take the risk? Or should I move the little guy to a small tank attached to the big one until it gets warmed up? Thanks!