Your requirements will depend on how the tank is set up and where its set up.
Are the pumps in your sump (submersible) or dry, what lighting do you have. What is the airflow around your tank and lighting like, does it have direct sunlight on it?
Chiller required if the tank heats up by more than 1 deg during the day.
The setup I have doesn't seem to require a chiller as the max temp increase I have seen so far is 1/2 deg F. However all my pumps are external now and I have great airflow between the tank and the light. When the pumps where in the sump and the lights didn't have as good of air flow around them I was seeing 2 deg F during a mildly warm day.
Heater = must have for tropical fish.
|