Is there a perfect temperature for corals? I hear 70-80 but what’s the best temp. Is it 72-75, 75-78 my problem is now that the Ac is on my heaters run at night this is very inefficient. I would like to lower my temp but wonder if cooler temps effect growth or color.
I read a good article on this, I will have to look for it again. Either Tropical Fish Hobbyist or the now defunct Aquarium Fish International. In short coral will grow faster at a higher temperature but will reach a point if too high when it will expel zooanthalle causing bleaching. Different corals bleach at different temps, but most sps will begin severe bleaching above 82F. I would recommend not going above 80, even that is precariously dangerous. Some of my sps bleach at 81. A 79 temp is the high end of safe. Most will say 77. My experience is to give wiggle room, stay around 78.
here a little article on it, a little dated but still good
That is a good article. I am now turning heaters on at 75f so it won’t go lower than that. It varies a lot but I think that builds more resilient corals. I’m afraid to get the temp too low but it’s frustrating knowing every night I have 14-1500 watts of heaters on while my Ac is running. Ill keep working on ways to make it work but 76-80 is usually whet my tank is and has been so I’m hoping 1 degree won’t make a difference
Dunk. What type of house do you live in?
Perhaps the solution to the problem here is not in the fish tank but in how you control your HVAC system. Give me some details on your setup, there may be a way to give that room or floor setback temps to keep your ambient temp warmer so that your tank won’t get too cool at night.
What temperature do you have your AC running at? You should be picking up some temperature over your ambient so if you are dropping below 75 degrees, you’re house must be chilly 
It’s a two story with basement I sealed my returns and supplies with silicone tape and mastic tape I’m going to get duct sealant too. I wired in dehumidification to my hvac system and shut vents to cool the 2nd floor is nice. The temp is set to 79 during the day 74 at night basement is 70f and 55% rh. I have a 3’x4’ open tank an open 75g and an open sump with a scrubber so my problem is too much evaporation and its in the basement with supply leakage. I do hvac service so I know what to do there. Just wondering how low I can go without sacrificing coral health
No need to tell you about HVAC then! I didn’t realize it was in the basement. My basement sits around 68-70 year round so I see what you’re saying now.
Yeah the ductwork is metal so every joint leaks I did get some duct seal and applied some last night and will keep doing it until its all sealed. My goal is to have the basement around 74. If I can get close to that I think the tank will stay about 76 at night.
Tim, just buy a new house :
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Ha I want too real bad