It's a 90 gal tank, and they need to keep the tank at most 15F above ambient. (60F house, 75F tank max) I have used these heaters for years already, so it feels like there's an equipment problem. On Mon, Dec 7, 2009 at 12:08 PM, R. Slettevold <Slettevoldr@comcast.net>wrote: > Hi Matt, > > It may not be the heaters, thermostats, or thermometers. It could be that > the heaters are not properly sized for your conditions, especially with > this > very cold weather! > > How many gallons is the aquarium that you have the two 250 watt heaters in? > What temperature are you trying to maintain in the aquarium? What are the > maximum and minimum room temperatures where the aquarium is kept? > > 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