how hot is too hot?

[tibob32]

With summer at the doorsteps the overheating question is poping up. I live pretty up north so I don't expect very high heat often, but was wondering how high I could let the temp go up before having to act? SPS wise obviously

 

[shaggy14]

Anything over 86 and I worry. I've kept my tank at 84 before to speed up growth but it was to close to the limit for me. One day the fan didn't kick on and I melted all my coral. I keep it under 80 now

 

[luv4qt1004]

o wow. mine is at 80 right now. but im sure during summers it'll go back up to 84ish. will this be ok?? isnt it all about stability? as long as it doesnt get too hot too quickly or too cold too quickly.

 

[Amphiprion]

Anything over 86 and I worry. I've kept my tank at 84 before to speed up growth but it was to close to the limit for me. One day the fan didn't kick on and I melted all my coral. I keep it under 80 now

That is about the point I would begin worrying. Anything 86 and over for any real length of time is going to be an issue in most cases. Corals that are already kept in higher temperatures may be more able to tolerate those kinds of temps longer without any lasting or even visible problems.

 

[Peter Eichler]

High 80's is when things start to get dangerous for a majority of corals. Also, no, it's not all about stability and the whole "temperatures must be kept stable" stuff is complete and total nonsense. There's nothing stable about temps in nature and you really only need to worry about temps when they get close to or outside of the normal range, which for most Indo-Pacific reefs is around the mid 70's up to just below 90.

 

[fijiblue]

There's nothing stable about temps in nature and you really only need to worry about temps when they get close to or outside of the normal range, which for most Indo-Pacific reefs is around the mid 70's up to just below 90

I beg to differ. Most of the bleaching that Fiji has experienced has been from temperatures rising to 84 degrees, but staying there for longer periods of time. To go 84 degrees in our tanks is asking for trouble as the dissolved oxygen is no where near the levels as in the ocean. That is not even taking into consideration the large increase in the production of bacterias. I agree that we have room to play with temp, but the extremes mentioned are down right dangerous.

 

[Stripe01]

Last yr my old tank went up to 86 two days in a row, which resulted in half of my sps bleaching and dieing. 84 is cutting it way to close.

 

[tibob32]

hmm, I think I'll be adding an AC to my window pretty soon. Thanks for the input people. My tank went up to 81 on a very warm april day. I can't imagine what july's top heat would do

 

[Amphiprion]

I beg to differ. Most of the bleaching that Fiji has experienced has been from temperatures rising to 84 degrees, but staying there for longer periods of time. To go 84 degrees in our tanks is asking for trouble as the dissolved oxygen is no where near the levels as in the ocean. That is not even taking into consideration the large increase in the production of bacterias. I agree that we have room to play with temp, but the extremes mentioned are down right dangerous.

Fiji's waters are a bit cooler than than the average. I've maintained 82-84 for a long, long time without issues.

 

[MrKite24]

I set my chiller to 79 so it swings from 78 to 80. I try to keep the tank under 82 with less than a 3 degree swing over 24 hours.

 

[Amphiprion]

Something I should've added to my reply above was that those temps I maintain are still close to what is considered corals' maximum. Unless you have safeguards in place (preferably redundant ones), it may not always be the best idea. I'm confident in the cooling mechanisms I have in place, though, so keeping those temps have never been a problem for me.

 

[EllieSuz]

I cool the house in the summer, but I also strongly recommend a controller for a couple of reasons. First, heaters are notorious for sticking in the "on" position and a controller will cut the electricity to the heater above a set point. But, more to the point of this thread, a controller will operate a fan when the temperatures get too warm. I have a clip on fan pointed down on my sump. You will be amazed how efficiently this inexpensive device will keep temperatures in check. We can argue all day about how important stability is in our systems, but the important issue is stopping overheating. My solution has been a ten dollar fan.

 

[imisky]

I have to agree with everyone that says 84 is as high as i would go. Usually i turn my chiller on at 79-80 and when it starts to get ti 82 i bring out the fans.

 

[tibob32]

I cool the house in the summer, but I also strongly recommend a controller for a couple of reasons. First, heaters are notorious for sticking in the "on" position and a controller will cut the electricity to the heater above a set point. But, more to the point of this thread, a controller will operate a fan when the temperatures get too warm. I have a clip on fan pointed down on my sump. You will be amazed how efficiently this inexpensive device will keep temperatures in check. We can argue all day about how important stability is in our systems, but the important issue is stopping overheating. My solution has been a ten dollar fan.

That's very true. MY RKL is a very precious piece of equipment and would recommend it to anyone

 

[Peter Eichler]

I beg to differ. Most of the bleaching that Fiji has experienced has been from temperatures rising to 84 degrees, but staying there for longer periods of time. To go 84 degrees in our tanks is asking for trouble as the dissolved oxygen is no where near the levels as in the ocean. That is not even taking into consideration the large increase in the production of bacterias. I agree that we have room to play with temp, but the extremes mentioned are down right dangerous.

Perhaps a mean temperature of 84 degrees, but they're certainly not bleaching because the water is hitting 84 degrees, if that was the case just about every coral in the Indo-pacific would be bleached and dead.

Also, the dissolved oxygen argument always has been and always will be a weak one. The difference between saturated oxygen levels at 80 degrees vs. 85 is is so small that it's barely even worth discussing. In addition, modern reef tanks, especially with the typical high flow and protein skimming of an SPS tank, aren't going to be all that far off those of a natural reef. In short, if you're having a problem with oxygen levels from running your tank temperatures 5 degrees warmer, you have been undercirculating your tank all along.

I'm certainly not suggesting people starting maintaining their tanks in the high 80's, or even mid 80's. However, if you tanks are run around 80 degrees normally and the corals are used to a little fluctuation, there should be little issue with the temps hitting mid to high 80's on particularly warm days. I've messed around with temperature quite a bit on my tanks the last 5 years and was regularly having my temps hit as high as 88 during the day without any bleaching or stress issues.

 

[fijiblue]

Perhaps a mean temperature of 84 degrees, but they're certainly not bleaching because the water is hitting 84 degrees, if that was the case just about every coral in the Indo-pacific would be bleached and dead.

It has been proven that the corals begin to shut down respiration at 84 degrees - I wish the search function worked as this was brought up about a year ago and I linked the article. In Fijis case, the extended stay at this temperature caused the bleaching. Does this mean your coral will die at 84 degrees? No, but it certainly makes it the max temp to work with - especially in our closed systems. Have waters reached higher temps? They sure have, but does that mean we can to? Perhaps we should ask how the reefs looked when the temps exceeded that - I would guess not good at all.

In addition, modern reef tanks, especially with the typical high flow and protein skimming of an SPS tank, aren't going to be all that far off those of a natural reef.

I don't agree with this statement at all. In order for us to achieve a decent oxygen transfer rate with our equipment in our closed systems, we would have to circulate more than half of our tank volume through the skimmer in a very small amount of time. That is not mentioning all the things working against you in your tank to achieve this higher DO.

Your previous statement was a few degrees below 90 was ok - at least you are changing it now to lower than mid 80's. I can agree with that.

 

[duastina]

I keep my tank at 78, sometimes it dips to 76 at night, is that bad?

 

[Michael7979]

Just don't allow it to change rapidly. That to me is a biggy.
And keep it below 85. Thats the two things I aim for.

 

[Peter Eichler]

It has been proven that the corals begin to shut down respiration at 84 degrees - I wish the search function worked as this was brought up about a year ago and I linked the article. In Fijis case, the extended stay at this temperature caused the bleaching. Does this mean your coral will die at 84 degrees? No, but it certainly makes it the max temp to work with - especially in our closed systems. Have waters reached higher temps? They sure have, but does that mean we can to? Perhaps we should ask how the reefs looked when the temps exceeded that - I would guess not good at all.



I don't agree with this statement at all. In order for us to achieve a decent oxygen transfer rate with our equipment in our closed systems, we would have to circulate more than half of our tank volume through the skimmer in a very small amount of time. That is not mentioning all the things working against you in your tank to achieve this higher DO.

Your previous statement was a few degrees below 90 was ok - at least you are changing it now to lower than mid 80's. I can agree with that.

Extended stay at 84 degrees? That's bordering on impossible on a reef as far as I know. The temperature is always fluctuating and there are usually noticable swings from day to night so there's some part of the story that you're not telling us here. I also don't see how anything you've said that "certainly makes 84 degrees the max temperature to work with".

Again, I routinely and on purpose had my reef hitting 88 degrees during the day and corals thrived. I don't see where I changed anything, nor do I see where I daid keep it lower than mid 80's... We're not talking about what temperature people should maintain their tanks at, we're talking about at what point it gets dangerous. I still stand by the belief that most corals will be able to tolerate high 80's as long as they haven't gotten been subjected to lower than normal and stagnant temperatures for extended periods of time.

As for the oxygen levels, until one of us comes up with some sort of proof we're just spinning our wheels. The fact remains that rising temperatures aren't going to have a big enough impact on oxygen levels in a typical SPS reef to make one shred of difference in the health of your ihabitants.

 

[Peter Eichler]

I keep my tank at 78, sometimes it dips to 76 at night, is that bad?

It's a little on the low side IMO, but I wouldn't go as far as bad.