Hey friends,

So i have always had planted freshwater tanks but have recently dived into having a reef setup.

My heaters keep the tank at a stable 78 degrees but when I turn the halide lights on for the 8 hours during the day the temperature turns to 80 degrees. The light is already hanging pretty high and i do not want to move it.

Is this okay? The tank is a 36 gallon bowfront so the temperature change takes awhile. Is this causing stress for my corals/fish? The tank seems very healthy.

Thank you for your time.

Let me start off by saying I know nothing about keeping salt water anything.

That said I think you'd be just fine! If you think about the water out in Hawaii or something and the reefs there - they have a typical temperature but it fluctuates down a bit at night I'm sure and then when the sun is blasting it it's bound to get knocked up a notch or two. A two degree flux can't be that devastating, right?

But again... I don't know a thing about salt water tanks. :D

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I like big fish tanks and I can not lie. You other brothers can't deny.

Diurnal temperature changes are very normal in many aquatic environments. Even in the tropics temperatures drop when the sun goes down. The Amazon River isn't kept warm by Electric Heater but by the sun, so when it goes away the River starts to loose heat. Temperatures also drop in a creek when a big thunderstorm dumps a lot of water on it. Temperatures could drop as low as 10F.

In a saltwater tank your hitting into the higher end if things, but still ok.
Think about putting a fan (not to high speed) aimed at your lights, so it doesn't amplify evaporation to much. Or drop the temp on the thermometer, or unplug it for a few hours during the day.
Tidal pools and lagoons can fluctuate in nature, but deeper water where corals live stay pretty constant.
The danger is if it goes over the 80 for some reason.
Who knows...you may get a heat wave in Minnisota...lol

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"Buddha in your tank"

What neon says is very accurate. That small of a temperature fluctuation should not be that big of a deal. Temps of over 84 for extended periods have given me problems during the hot summer months but my tank goes from 76 at night to 80-82 during the day. You should be fine I hope that helps!