i have a rena cal 200W running in my 65G hex tank. I have it set at the minimum temp of 66F and my tank water is at a constant 82F...what gives? My ambient room temp is 78F. I dont believe that 200W is too much for my 65G tank...am I wrong?
The heater may be defective but more than likely your tank is just way too high. The lights and other devices may be keeping your temp. up. As I am sure you are aware heaters do not cool things down.
It is a good idea to have two heaters in a tank just to be sure that at least one Thermostat/heater is working properly. They do fail by just not working at all or sticking on all of the time. The tell/tale light is nice but a hand test daily tells you if the tank is too cold or getting too warm. Your hands are very sensitive to temp. variations.
On the subject of putting your hands in a tank...be careful! There are a lot of electrical devices in a tank and shorts are common. If your fish act hinky or you get a tingle, especially on a small cut, you have a short. Stray electricity is dangerous. Turn off all electrical devices before working in a tank. Repair all shorts quickly.
I have never had a heater go bad but the Hobby abounds with stories so it can happen. Your heater sounds OK but as with any device calibrate it with a Thermometer you trust and set it for where you want it to be. If you have two heaters set one a couple of degrees f less than what you set the main one for.
i have no lights at this time. this an unplanted tank that im getting ready for plants. like i said, the heater is set at 66F and my water is 82F (a couple degrees higher than ambient temp). i tried bumping the heater setting up to 75 the other day and my tank just got hotter, approaching upper 80's. I am thinking that the heater is defective...it is atleast 5 years old.
With the room temperature at 78F you don't need a heater at all. It could only warm up the water more, not cool it down. I don't use a heater in my 45 gallon tank, because the room rarely ever gets as cold as 65F, and only in the winter. That size tank cools down pretty slowly, so if the room is warmed up every morning back to 78F it probably will never be too cool.
in the winter the house goes down to 68 at night and about 70-71 during the day. i should use the heater then, right? I mean, for my tropical fish...they probably dont like it that cold. id probably keep it around 78F preferably.
Sounds like a bad heater. Here is one way to check: Unplug it, remove it from the tank and monitor the situation. If the tank still stays that hot then it is the motors of whatever pumps, filters etc you have running that are heating up the tank. If the tank cools to about room temperature then the heater was coming on (even set so low) and is faulty.
i know for a fact that the heater keeps coming on. it has a light when its on and the light is off when it is not heating. even though the water is at 82F it keeps coming on...faulty heater i believe and i will replace it. thanks diana.