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