Water Temp.

[MikeS]

Since I add M/H lighting I find my water temp. raising to 83 degrees during the day. When the lights go off at night it will drop to 79 degrees. Is this a problem? Hate to think about having to add a Chiller.

[erasmu]

You might try raising your heater setting to keep the tank at 80 or 81. That would narrow the variation between night and day temps. Certainly temps in the 82-84 range are not a problem for reef tanks.

[HuBu]

you should try to limit the fluctuation between temp at nite and temp during the day. my tanks temp is usually 30C which is like 86F.

[nickg]

FWIW, and IME, my tank fluctuates between 80 and 84, I've yet to see a problem. The steadier the better.

[Rick O]

If it didn't drop down to 79 at night then the temp might climb higher in the day. I use a fan on my tank at night to try and lower the temp as much as possible before the lights come on. That keeps my tank from going into a dangerous temperature range during the day. I would leave it the way it is. Temps fluctuate on the natural reefs.

[erasmu]

Rick may be right, but that did not occur with my 55g tank. My PCs raised the temp from 77-78 up to 82 during the day. I increased the heater setting to 80. The light still only raises it to 82, but now the variation is much less. The room my tank is in is kept at 76. Any variables in your setup could result in differences, but I wouldn't assume that increasing the lower set limit for your tank will automatically raise the peak temp by the same amount. Having fans in the light hood and strong water flow at the surface is very important. Good luck with your tank.

[MikeS]

Thanks for the input. I'm going to raise the night time temp. to reduce the variation.

[Mr. Ono]

Am I the only one that uses a chiller??? My tank stays between 78 and 80 degrees 24/7.

My office gets into the 90's at times (no A/C) and nothing other than a chiller would keep a tank cool. I know it is a big investment but you corals and fish will be happier. Isn't that what credit cards are for?:

At coler temps, the saltwater has more O2 and fish's metabolism are slower meaning less waste (fecal matter).

[erasmu]

78-80 is a pretty good temperature for fish. They can handle (not necessarily enjoy) even cooler temps. Reef tanks are now recommended to be kept at higher temps. Values vary, but most agree 82 is a good target. Tropical fish also do very well at the higher temp, but the bioload cannot be pushed too much. Maintaining 82-84 isn't too hard in an air conditioned home or office, even with intense lighting. A couple of fans in the hood are very helpful.