I have my most accurate temp controller probe in the tank itself. I also have a separate thermometer in the sump. I keep a 300 watt Eheim heater in the overflow and another 200 watt in the sump.
The sump temp is always a few degrees higher (about 4) than the tank. So I'm guessing that if your temp controller is based in the sump, that the tank is actually colder by a few degrees (unless the heaters are in the tank)
This poll doesn't apply to small AIO tanks.
The sump temp is always a few degrees higher (about 4) than the tank. So I'm guessing that if your temp controller is based in the sump, that the tank is actually colder by a few degrees (unless the heaters are in the tank)
This poll doesn't apply to small AIO tanks.