how hot is too hot?

[Amphiprion]

I agree on the DO concentrations. Water can still hold more than enough oxygen at those temperatures.

I don't recall where I had read it (Shimek, I *think* and somewhere else), but peak coral diversity actually occurs in areas that average 84--on the literal brink. A tad higher and they wouldn't be able to survive. Their optimum is almost right at their maximum. That's why I don't worry from 80-~84. The only issue with that reading in my tank is that it may be a bit off, so 84 may be 85, etc. That's why I prefer to err a degree or two lower just in case. My controller is supposed to be accurate, but only to a degree or so.

 

[fijiblue]

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".

Hmmm - not sure what you missed here. There is literature out there - this is not my opinion, but cited in credible literature. Again, I wish the search function worked as I already posted the literature in another article.

gain, I routinely and on purpose had my reef hitting 88 degrees during the day and corals thrived.

Im not sure where you are thinking these corals are thriving. Again, it has already been proven that respiration begins to shut down at 84 degrees. My apologies that I cannot link the exact literature, but a little searching and you can probably find it. If a person's respiration is shutting down, I would hardly consider them thriving

 

[Peter Eichler]

Hmmm - not sure what you missed here. There is literature out there - this is not my opinion, but cited in credible literature. Again, I wish the search function worked as I already posted the literature in another article.



Im not sure where you are thinking these corals are thriving. Again, it has already been proven that respiration begins to shut down at 84 degrees. My apologies that I cannot link the exact literature, but a little searching and you can probably find it. If a person's respiration is shutting down, I would hardly consider them thriving

I'm not missing anything, you're the one missing the information you're citing Also you seem to be claiming that water is staying at a constant 84 degrees and causing this, which I can assure you is NOT the case. My guess is the literature you're refering to is talking about the mean temperature rising. But without you producing the information you're claiming proves all these things it's just that, a guess.

I however have observed corals growing and thriving in an aquarium that hit 88 degrees on some days and at least 86 every day for several months. I'm not sure how much more clear I can make that to you. These is actual observations on my part, and if those temps were affecting respiration it didn't seem to show negatively in growth rates or visible coral health. Afterall, these aren't people we're talking about, they're corals...

 

[fijiblue]

LOL. I think I am done here as you truly are missing the point. I trust literature over your personal observation as a hobbyist any day as I am sure others would as well. Unfortunately, I can't produce the exact journal (was done in Japan for those of you interested) as the RC search function is not working and I am on a new computer without my bookmarks. There are plenty of more if you do your homework. Here is one of many studies done. Please note the temps:thumbsup:
A study conducted by researchers from the University of Puerto Rico found that 54 days of 29.5 °C water temperatures or 10 days of 30.5 °C water temperatures correlated with severe coral bleaching.

Taken from:
http://www.aoml.noaa.gov/general/lib/CREWS/Cleo/PuertoRico/prpdfs/winter-surfacetemp.pdf

Here is a graph of Fiji's water temp over the course of the last 12 years. Note that every year consists of almost 10 months out of 12 below 84 degrees. Also note the two years that showed extremely higher temps above 84 were the years Fiji lost a lot of it's coral reef due to bleaching.

If this happens in the ocean, why would you want to go above 84 degrees in your tank? Especially when dealing with more than just a coral's respiration shutting down, but also a large increase in bacteria blooms which are in part why reefs bleach.

 

[Peter Eichler]

Heh, those are averaged or mean temperatures. I totally agree that it's a good idea to avoid a mean temperature of 84 degrees in an aqaurium, but that has little to do with what is being discussed in this thread. Most likey those months where the average temperature is 84 degrees there are days where high temperature is hitting the 90's. As far as I know the real bleaching danger is when you start getting above the typical seasonal highs, not that the temperature is averaging 84 degrees over the course of a day.

I'm not sure why you're even bringing up info based in the Atlantic as it's not going to relate very well to Indo-pacific corals, which is what's being discussed.

 

[fijiblue]

Again, do a little research and you will find more than just the Atlantic. I didnt know I had to spoon feed you

 

[sanababit]

well 86 is when i turn on the fan, i am sure the tank can take more but i really dont want to take a chance....

sana

 

[greenbean36191]

The average temperature on coral reefs worldwide is about 82. The average reef sees a yearly maximum temperature of 86. There are reefs that are cooler (like Fiji, Hawai'i, The Bahamas etc.) and there are reefs that are hotter like in the Persian Gulf. http://icb.oxfordjournals.org/cgi/reprint/39/1/146

There is NO set temperature at which corals' respiration declines or bleaching begins. See this paper where they measure the daily temp on two parts of the same reef (which stays above 29.5 C for almost 3 months at a stretch) and compare respiration of the same species of coral as temps increase. There is no decrease in respiration until 33 C (91 F). http://www.biol.sc.edu/~helmuthlab/Publications/InJournals/2005/CastilloHelmuth05.pdf

The rule of thumb is that the stress threshold is 2-4 F above the seasonal maximum temperature and is a product of acclimatization. On some cold reefs, stress can begin at temps as low as 82 and on other reefs, the onset of stress can be above 90 for the same species of corals all depending on the temperatures the corals were acclimatize to.

Personally, my tank typically sees a maximum of about 86 in the summer. It will occasionally get as hot as 88, but at that point I start to get concerned and I'll usually kill the lights.

 

[joshrules123456]

82 for me, any higher, I turn on the celing fan. Over 85 I turn off the lights and unplug the heater. (yeah, im too broke to afford a controller) my tank has spiked up to 88 degrees, and I havnt had any problems. Ive said it before, and I'll say it again, as have many people: CORALS ARE ANIMALS, AND THEY WILL ADAPT (wish I knew how to underline that) TO THEIR ENVIRONMENT!!! that beeing said, I wouldnt push it past 84 as a target temp though.

 

[fijiblue]

The paper actually says over 89.6 degrees, not 91 degrees as far as decrease in respiration. Also, the coral was subjected to the high temp for only an hour. This would not constitute a day or extended periods at these higher temps. If respiration decreased that quickly at that particular temp in an hour, that means the threshold or maximum temp for this coral (a single coral species by the way that is not an acropora) would be significantly lower than the temp stated.

Thanks for the article - it was a good read.

 

[fijiblue]

Here is a good read on vibro and temps,
http://www.int-res.com/articles/meps/147/m147p159.pdf

 

[Peter Eichler]

Again, do a little research and you will find more than just the Atlantic. I didnt know I had to spoon feed you

When someone refutes something someone else is saying it's usually up to the person refuting it to provide the information to the contrary, but thanks for being a jerk about it. :thumbsup: You've done nothing to show that respiration stops in corals in Fiji at 84 degrees, which is the main basis for your argument.

 

[fijiblue]

I did provide it - you just didnt read it...

 

[Peter Eichler]

I did provide it - you just didnt read it...

Sorry if I missed a link or the name of the study, I still don't see it...

 

[fijiblue]

Seriously? You bounce around between what you want to argue about. I like how you edit your post after my reply for your benefit . I am done with you. You keep running you tank to 88 degrees if that is what you wish to do - Im glad it works for you.

 

[bsylv91]

in the summer my tank goes from 78 to 85 every day and my SPS do fine.

 

[Peter Eichler]

Seriously? You bounce around between what you want to argue about. I like how you edit your post after my reply for your benefit . I am done with you. You keep running you tank to 88 degrees if that is what you wish to do - Im glad it works for you.

Seriously? You bounce around between what you want to argue about. I like how you edit your post after my reply for your benefit . I am done with you. You keep running you tank to 88 degrees if that is what you wish to do - Im glad it works for you.

I don't run my tank at 88 degrees as it was just something I tinkered with. My point all along has been that things don't get dangerous for corals until the high 80's in most cases, something I've maintained throughout this thread. So, I really don't see how I'm bouncing around. You're right, it's probably best if we both just move on.

 

[joshrules123456]

for the love of god someone lock this thread!, (its gotten childish) i am rubber, therefore, you are glue!!

 

[graysmurf]

I also do not like to run over 86 degrees. Have gone as high as 90 in the past and corals did not do well.

 

[RagTopMan]