[Chrisk-K]

My fish room is in the fully furnished basement and I set the temp of the basement and 1st floor at 68 at night. The thermostat's on the 1st floor, so the basement temp is lower.

My Rena 300W heater had trouble maintaining the temp of my 40 g tank at 76 last week when it was cold (mid 20's at night). In the morning the tank water temp was a couple degrees below 76 but eventually went up to 76.

So, I guess 300W is not enough. How much wattage do I need to keep tank temp 10 (or more) degrees above room temp?

 

[crossbow]

It's 65-66F in my home, in a 46 Gallon with a fluval E 200 watt, and my temp is stable at 75F without issue.

I know your basement temp was set to 68 at night..but how cold did the basement actually get? I'm guessing it didn't stay at 68F, or your heater is having problems functioning properly.

If your basement temp is dropping way below your heaters capability (house heater) of maintaining it, you might want to spend your money looking into insulation, or a possible area of heat escape down there. That would end up saving you money in the long run, instead of filling your aquarium with more heaters. Otherwise I'm going to point at your aquarium heater as the culprit.

Note: Someone just pointed out to me that I might not be having issues because my aquarium is acrylic... =/

 

[fish h20]

Make sure your heater is in an area of high water flow if it isn't already.

 

[Chrisk-K]

It's an acrylic tank.

Well, it turned out that my wife sets the basement & 1st floor temp at 60 before going to bed and sets it back to 68 in the morning because all bedrooms are on the 2nd floor! I usually go to bed earlier and wake up later than she, so I didn't know that. Something's fishy