I have been looking at the Eheim Trutemp for one of my 5 gallon tanks. I've been told by some people that a 50 watt would be way too powerful. The reason I was thinking 50 watt is that the house temperature in the Winter is often between 16 and 18 degrees. I have a 50 watt Aqueon in another tank, also a 5 gallon and never had a problem. What do you guys think? Is the Eheim Trutemp even worth looking at? Thanks.