One heater has an indicator, which comes on as expected. Both are warm to the touch though I could swear that they have felt hotter in the past. I'll figure out if a heater has failed eventually. For now I just bought another 300W heater to take up the slack, for the sake of the fish I had to make a change today. MS On Mon, Dec 7, 2009 at 6:53 PM, Seattle_Aquarist < Seattle_Aquarist@comcast.net> wrote: > Hi Matt, > > Based on what I can find, if both heaters are working properly and the tank > has good circulation you should not have a problem. I think Shango may > have > hit on one possibility; one of the 250 watt heaters has failed or is turned > down too low. If only one heater is working on that 90 gallon, heating > capacity would be undersized for your tank and during a cool night the > aquarium temperature would drop. If the heaters have indicators, do both > light? If so, do both heating elements get warm? (Obviously check with > the > heaters in water!! LOL) > > Roy > > > > > > _______________________________________________ > GSAS-Member mailing list > GSAS-Member@thekrib.com > http://lists.thekrib.com/mailman/listinfo/gsas-member > _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member