You may consider putting a thermometer right next to one of the heaters and see if it's at the temperature that you want. If it is, you have a flow problem. If it isn't try turning up the heaters. If your house is particularly cool as well, that could be the problem. I ran 1x 250 watt heater in my 29 gallon tank, but it was full of rocks, not plants. It kept it at 80º with no problems. I used Visitherm Stealth heaters (find them cheap online somewhere, print out the page, then head into petsmart and they'll price match!) On Mar 30, 2009, at 4:16 PM, Kypros Hostetter wrote: > I have a heavily planted 29 gallon tank and have been operating a new > heater rated at 55 gallons. I cannot seem to keep the temperature > at 76 > degress, it keeps it at around 74-73 degrees. Today I added a second > heater, in the other corner and even with it, it is still maintaining > the temperature lower than I want. I do not think both heaters are > malfunctioning. I suspect that the heaters, in the back of the > tank, do > not receive sufficient water flow to heat the whole tank. In other > words, I think they heat up the water around them which is not > circulating sufficiently in the tank. I have an Eheim 2215 in the > tank, > which should have sufficient flow for the tank size but I wonder if > the > plants inhibit flow enough to cause heating problems. Has anybody else > had this issue? If so I will probably put a powerhead in the tank to > move water around better. > > Kypros > _______________________________________________ > 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