Temperature swings - hourly, daily etc.

[Reef of Fillory]

I recently hooked up a metal halide fixture to my tank with a fan.

I am seeing the fan turning on/off throughout an hour period.


Heater settings:

Fan Settings:

Last 1 hour (Metal Halide has been on for 1 hour previous to this clip):

Should I tighten the temperature parameters on the fan? If I run the fan continuously, I might have an issue with the heater fighting the fan, and lowering the water temp too significantly?

Thanks everyone!

 

[Crabs McJones]

I use the JBJ trutemp controller, and this allows for +/- 1 degree swing from my set temperature. I set it to 78.5 so the tank will drop to 77.5 and the heater will kick on until 79.5 and then kick off. This happens over the course of a couple hours. I am however looking at getting a Cobalt Neo-Therm heater soon as I want my temp to stay more stable. But my corals and fish don't seem to mind the temp swing, and its over the course of a couple hours, so it's not a major drop or increase to quickly.

 

[Rick Krejci]

I do my heater setpoints 0.5F apart and my fan's lowest setpoint 0.2F above that and then the fan setpoints 0.2F apart.
For example, the heater is at 77.3 to 77.8 and the fan's 78.0-78.2. Still keeps within +/- 1F, but doesn't cycle too much.

 

[pdxmonkeyboy]

You could always throw a line of code in there if heater on then fan off.

I think as long as your temp is within 2-3 degrees between light on and off you are just fine.