tank temps for mixed reef?

[d_icemand]

What is the ideal tank temps for a mixed reef??? And then what is the minimum and max temps you can let your tank get too without damage to the reef? I get so many mixed answers on this. Should the swing of temps be no more that 2 degrees?

[jhildebrand]

well, depending on who you talk to, you'll get an answer of 76 to a max of 82. i keep mine at 78 with a ranco controller checked by a pinpoint thermometer. i like 78 because if your thermometer is off a little you're still safe. it gives you a margin of error. i don't like more than a 2 degree swing. just my two cents

[NirvanaFan]

Let it swing. I like mine to range from 80 to 84, but anything from 77-86 is ok in my eyes. Your corals will get used to the temperature swing. Contrary to some people's belief, the temperature on a reef swings more than just a couple of degrees at times. Ever been swimming in an ocean or lake and felt a warm or cold pocket of water? The same thing happens on the reef. I wouldn't let the temperature swing more than 7 or 8 degrees in a day, but 4 or 5 is perfectly fine (some people recommend it).

If your corals aren't used to a temperature swing, a swing of 4 or 5 degrees could kill them.

While there is a minimum and maximum temperature that corals can live at, it generally isn't reached in home aquaria. There is no set temperature where corals will bleach. Sometimes corals are exposed to the full midday sun during low tide. Surely they get hotter than 82 degrees.

[MileHighFish]

+1 Nirvana.

[stricknine]

I keep mine at 80 because on hot days it would be impossible to keep below that without a chiller.

[NirvanaFan]

Sricknine, have you tried blowing a fan across the water surface?

[stricknine]

Yep, thats what lets me cool the tank to 80! Otherwise it would (and has) hit 90.

Not all igloos here in canada, summers are pretty hot and I dont have central AC.

[NirvanaFan]

hahaha, I've been to Edmonton in July, it was definitely warm.

[d_icemand]

thanks. I let mine go from 78/79 in the mornings up to 82 in the afternoons. I've heard thats bad but my corals and fish seem ok. I was just looking for the best for my tank.

[phish guy]

winter=78-78.5 F

summer=80-82/83 F

[bmxdad]

90g tank goes from 77.5 to 80 in winter and up to 82 in summer
29g goes from 75 to 80 but have a small chiller on this tank for summer.

[greenbean36191]

A temp from 77-86, with an average around 82 is ideal. This is the temp regime for an "average" coral reef in the wild.

As long as they are at least fairly frequent and don't go beyond the average high or low temp for the tank, temp swings are fine- regardless of how quickly they occur. There is no evidence that they are harmful to any reef organisms. There is however, evidence that they can reduce the sensitivity of corals to heat stress.

i like 78 because if your thermometer is off a little you're still safe. it gives you a margin of error.

I don't mean to pick on you, because probably the majority of reefers think this way. This isn't the case though. The thermal limits of corals are not set genetically. They are set by acclimatization. The upper limit is determined by the average seasonal maximum temp. As a rule of thumb you always have the same margin of error (~2-4 degrees) regardless of whether the max is 78 or 84. You don't start running into absolute limits until around 90.

And then what is the minimum and max temps you can let your tank get too without damage to the reef?

See above. There are absolute limits to what corals tolerate, but in almost all cases conditioned limits are going to be more important. These will set the upper limits about 2-4 degrees above the average maximum temp. There has been less study of lower thermal limits since they're not as much of an issue to modern reefs, but we do know acclimatization plays some role. We just don't have a neat little rule of thumb yet like with upper limits.

At the absolute limits, most corals can tolerate temps approaching 90, some into the mid 90s without issue as long as they've been previously acclimatized to similar temps. Most corals can survive temps into the 60s, again assuming prior acclimatization. If you were to take a coral from a tank that's constantly 78 and dump it into either situation, even after several hours of acclimation, you would kill or severely stress it.

[firsthesitation]

Typically mines between 78-82, depending on the time of the year and time of the day with the halides. I think you'll get from most of the reef keeping guys that we keep ours closer to 80 where most of the FOWLR guys I've talked with keep theirs closer to the 76-78 range.

Ideally too I believe (someone correct me if I'm wrong) you can actually help prevent some diseases at a higher temperature.

[Ranchhand02]

I run mine around 78-79

[jgln]

I lost my AC last summer when outside temps were in the high 90's and my tank got up to the low 90's for 2 days. I thought everything would survive until I got it repaired but I was wrong. I lost every bit of my very healthy frogspawn. I had 2 about 6"x6". Everything else survived.