Temperature fluctuations for SPS ok?

aaron186 · Nov 11, 2023

I just increased my lighting on my Acro dominated tank. I’m running 3 reefi uno pro 2
over a 4 foot tank at about 12 inches off the water. The lights run hot and have been heating my water. I was running the tank at 78-78.5 with apex/inkbird and it was pretty stable. Since the change my tank is heating up slowly through the day to 80 degrees and then falling back to 78 overnight when the lights go off. I keep my house at 74 degrees consistently (live in Florida).

Will this rise and fall of 2 degrees cause any issues in my tank? Should I just up my thermometer to 80 to keep it constant?

Btw I don’t have sump space for a fan/chiller

Lavey29 · Nov 11, 2023

It's not a big swing but doesn't give you much room for error either. I'd be worried at 81 or 82 as a temp swing. Can you add a fan to circulate the heat off the surface?

Mine went from 77 to 81 during power outage and SPS were ok with that but I'm sure not recommended.

DaJMasta · Nov 11, 2023

That's not a big swing, and I agree it's a tad on the warmer side of ideal, though unless your 74 F ambient temperature is rigorously kept, lowering it may make it slightly less stable, given the tendency to warm during the day. I'd lower the target to 77 F and just call it fine if it tops out around 79 F, but looking towards a fan (which increases evaporative cooling quite a bit) could be a good plan if you're spiking above 80 F or want some control over cooling as well as heating.

Macdaddynick1 · Nov 11, 2023

I have mine set beteeen 78-82, never had an issue. Some days it swings from 82 during the day to 78 during the night. Most of the time though it is based on the time of the year. Summer closer to 82 winter closer to 78.