Cooling your reef tank

[fragmatic]

It's not even a night/day swing. It can be an instant swing when a current shifts. Ocean temps are not uniform like in our tanks.

The point Ike was making is that if we allow our tanks to swing a little bit to replicate nature instead of letting them adapt to one constant uniform temperature, our corals will be less susceptible to stress if and when there is a shift in temp.

It is an interesting hypothesis at the very least. Certainly not ridiculous considering some prominent people within the hobby also share this belief.

I agree it is interesting and would be nice. I think we will get there. We have come huge strides in the last 10 years. I think until we learn a little more we need to stick with a steady temperature. As we make more progress I would expect it to become a standard practice for us to not heat or cool our tanks a few years down the road, letting them vary with the room and season. I don't see us there yet. The best is yet to come.

It seems to me, another reason we keep a steady temperature is for the sake of other inverts in our tanks who do not have the landscape area to seek out warm and cool spots to buffer those temperature changes in real reef cycles.

 

[Ike]

I agree it is interesting and would be nice. I think we will get there. We have come huge strides in the last 10 years. I think until we learn a little more we need to stick with a steady temperature. As we make more progress I would expect it to become a standard practice for us to not heat or cool our tanks a few years down the road, letting them vary with the room and season. I don't see us there yet. The best is yet to come.

It seems to me, another reason we keep a steady temperature is for the sake of other inverts in our tanks who do not have the landscape area to seek out warm and cool spots to buffer those temperature changes in real reef cycles.

We're there, too many people are affraid to give it a shot and are stuck with the gosphel from the early days of the hobby. Me, Greenbean, and a few others over on RC were trying to dispell this stability nonsense when it comes to temperature some years ago. People are certainly coming around and realizing that a stable temperature is among the least of your concerns in a reef tank. I experimented with it heavily and encouraged day to night swings on my 65 gallon reef for nearly 2 years. All of the corals in that tank thrived. I also pushed the envelope of lows and highs and kept the tank in the low 70's for a period of time and would regularly push it into the upper 80's.

The only time in all of my experimenting with different temperatures I saw outward signs of stress was when the tanks were too cold. It could have been unrelated, but it seemed particularly difficult to get certain sps to fully color-up in temps that low.

In short, there really isn't anything scientific to back up temperature fluctuation being a stressor for corals, as long as those temperatures are within their natural range and tolerance. There is scientific evidence to suggest that those fluctuations can help with thermal tolerance and perhaps make an event of an extreme high or extreme low less stressful on your inhabitants.

Day to night swings of up to 10 degrees is common on a reef, drastic and instant swings of 10+ degrees from a change in current or upswells is also common. Corals have adapted to this for many thousands of year, who are we to say a more natural habitat is wrong...

The whole stable temp thing came from freshwater fish and fluctuations making them more prone to certain parasites. However, there is no evidence to suggest that the same is the case for marine fish.

 

[Ron Reefman]

Stability isn't all it's cracked up to be... I think a tank that fluctuates anywhere btween the mid 70's and mid 80's is more normal and beneficial than the staggnant one temperature forever nonsense. Let the temp swing and let it get warm, it's more natural and will make your corals less prone to thermal stress. Day to night swings of up to 10 degrees is common on a reef, drastic and instant swings of 10+ degrees from a change in current or upswells is also common.

I hate to burst your bubble Ike, but there is absolutely nothing 'normal' or 'natural' about temperature swings on a reef in the real world. Over the course of a year the water temp on a reef may vary by 10 degrees (from 75 to 85 in the Florida Keys) but it doesn't go up or down by a degree in any 24 hour period. The air temp over a reef can swing quite a bit, but the water temp is very, very slow to change. And yes there are currents that can create a temperature change. But even that is only a few degrees and most of the time very temporary.

That said, I agree that tepmerature stability is much less of a concern than other parameters. I have serious doubts that swings of 10 degrees in a 24 hour period on a daily basis would be healthy for our corals, but they are typically more tolerant than the need to hold temps to reef standards.

 

[Zack]

Great topic! I've always wondered about temp swings. I keep mine steady at 79 day and night.

Sent from my VS950 4G using Forum Runner

 

[WesF]

I hate to burst your bubble Ike, but there is absolutely nothing 'normal' or 'natural' about temperature swings on a reef in the real world.

I hate to burst your bubble Ron Reefman but that is absolutely false. Check out this article.

http://www.reefsmagazine.com/forum/reefs-magazine/100587-great-temperature-debate-part-iv.html

"On the average reef we typically see daily temperature variation of 2-6F" while some areas have a normal 8-10 degree swing sometimes even getting up to 12degF.

 

[Ike]

I hate to burst your bubble Ike, but there is absolutely nothing 'normal' or 'natural' about temperature swings on a reef in the real world. Over the course of a year the water temp on a reef may vary by 10 degrees (from 75 to 85 in the Florida Keys) but it doesn't go up or down by a degree in any 24 hour period. The air temp over a reef can swing quite a bit, but the water temp is very, very slow to change. And yes there are currents that can create a temperature change. But even that is only a few degrees and most of the time very temporary.

That said, I agree that tepmerature stability is much less of a concern than other parameters. I have serious doubts that swings of 10 degrees in a 24 hour period on a daily basis would be healthy for our corals, but they are typically more tolerant than the need to hold temps to reef standards.

No sure where you're getting this from, but it's absolutely false. Temperatures on most reefs will vary typically from day to night by well over 1 degree. Also, shifts in currents and upswells can create dramatic and sudden changes of several degrees. This is a fact and there is plenty of scientific data to back it up, I'm not stating an opinion...

 

[Ike]

One last thing...

I'm not promoting someone trying to mimic dramatic day to night changes or sudden changes. However, having your tank fluctuate in temperature within a safe range from day to night may have some benefits and better equip your corals for dealing with more dramatic shifts should something go wrong. Also, the whole matching water temp on water change water is totally not needed unless you're doing a very larger water change.

 

[Ron Reefman]

Well Ike, I read your article and here is what I read:

"On the average reef we typically see daily temperature variation of around 2-6 °F. Coral reef animals of all sorts tolerate these conditions, granting that tolerance is one thing and the ideal may be another."

and

"At the other extreme are tidally influenced pools, backreefs, and lagoons like those on Ofu Island in American Samoa. Here the daily temperature variation is often 8-10 °F, and can be as high as 12 °F (e.g., 80-92 °F) with these swings in temperature sometimes realized in just a few minutes, as the tide comes in. These are the extremes though. On the average reef we typically see daily temperature variation of around 2-6 °F." That's not 10 degree swings Ike.

and

"I believe that the most appropriate temperature for most reef tanks, most of the time lies within the range 77-82 °F. A stable temperature is only potentially desirable if it is near this range, whereas a stable temperature well outside of this range is likely to result in lower growth rates, health problems and eventually death depending on how far outside this range the temperature reaches, the length of time spent at that temperature, and the sensitivities of the organisms in question."

Sure, they site a few examples of places that do have bigger swings, but that's not the norm and it's not good for the coral's health. You go ahead and believe what you want, but your own evidence says you are more wrong than right.

And then there is my reference (http://www.reefs.org/library/talklog/d_warren_011898.html) that says this:

"Q :How often can temprature changes in the order of +-2 degree's occur before it starts to have effects on the tanks inhabitants... as a general rule. Personally, I don't think that such a variation in the daily temperature has too much effect on the health of a reef tank.... but there are some previsors on this statement... the tank has to be healthy in all other ways, otherwise the additional stress the occurs due to the temperature fluctuations will take their toll, and cause some problems. I can say that my tank is currently fluctuating through 2.0 ^o C per day with the summer period. And none of the corals or fish, or any of the other inhabitants are showing any ill effects. And if you look at the data I presented, such variations are not out of place on a natural reef. But if you conditions in the tank are substandard, then the additional stress will be a problem. And that is why most people advocate that you minimise the daily temperature variation. Until you really know what you are doing, having the temperature fluctuate may just cause you further problems."

And take a look at this page:
http://data.aims.gov.au/aimsrtds/yearlytrends.xhtml
the graphs show daily water temps moving a few degrees over a few days at several reefs in the Great Barrier Reef.

 

[kracer1025]

I won't say who is wrong or who is right, but I will say I have ran my 90 sps reef for several years with rather large temp swings. I run a heater to keep temps from dropping below 77 deg f. I run 2 250 watt mh and temp could get as high as 84 deg on a regular basis. I have very healthy corals and great growth. I gave had all my fish for several years without problem. I would venture to say that temp swings even in our small ecosystems is not that much of a concern.

 

[Ike]

Well Ike, I read your article and here is what I read:

"On the average reef we typically see daily temperature variation of around 2-6 °F. Coral reef animals of all sorts tolerate these conditions, granting that tolerance is one thing and the ideal may be another."

and

"At the other extreme are tidally influenced pools, backreefs, and lagoons like those on Ofu Island in American Samoa. Here the daily temperature variation is often 8-10 °F, and can be as high as 12 °F (e.g., 80-92 °F) with these swings in temperature sometimes realized in just a few minutes, as the tide comes in. These are the extremes though. On the average reef we typically see daily temperature variation of around 2-6 °F." That's not 10 degree swings Ike.

I said it's common for some reefs to have UP TO 10 degree swings. What you just posted supports that, it doesn't refute what I said...[/COLOR]

and

"I believe that the most appropriate temperature for most reef tanks, most of the time lies within the range 77-82 °F. A stable temperature is only potentially desirable if it is near this range, whereas a stable temperature well outside of this range is likely to result in lower growth rates, health problems and eventually death depending on how far outside this range the temperature reaches, the length of time spent at that temperature, and the sensitivities of the organisms in question."

Sure, they site a few examples of places that do have bigger swings, but that's not the norm and it's not good for the coral's health. You go ahead and believe what you want, but your own evidence says you are more wrong than right.

It wasn't my evidence, someone else was nice enough to post it to show that maybe what I was saying wasn't so ridiculous... Really my only point in posting was to let the OP know that the 82 degrees is not a big deal (it may be very close to ideal) and that the tank dropping down at nigh to as low as 75 at night isn't as concerning or detrimental as most in this hobby would lead you to believe. I actually agree with the above for the most part, though his range may be a little low still. At least with the species that have been studied, optimal growth in tropical corals seems to be happen in the 82-84f range. Additionally, the average yealy temperature of coral reefs within what is known as the coral triangle is 82-83 degrees. So, if you want to talk about ideal, just about all of us are falling quite short of ideal. However, there's nothing to suggest that mid to high 70's is necessarily bad pr stressful to tropical reef inhabitants.

Studies have also shown that thermal stress will occur in nature at 2-4 degrees above the normal seasonal maximum temperature. This suggests to me that adapting corals to a range of temperature that would be common within their natural range may help to prevent loss when something such as a stuck heater, broken AC, or really hot day catches you off guard. No, just because it happens in nature doesn't mean we should try to replicate it, but I'm not advocating the extremes, I'm advocating staying within a known safe zone is for an overhwelming majority of the species we keep. In short, we shouldn't be so worried about our tank temperature and if it fluctuates. Also, if you've been maintaining your tank at 77 for years I would not suggest reading what I wrote above and boosting your new constant temperature up to 83 degrees all of the sudden. However, striving to get to 83 by allowing your tank to start fluctuating a bit and slowly raising your high daily temperature until you get to 83 might not be a bad idea. Though it's probably not a good idea for your electric bill... At the same time, my tank fluctuates and I've messed around with a lot of different temperture scenarios over the past 8 years. I haven't really seen stress from corals coming from tanks that I know were in tanks with pretty costantly stable temps. For those reading this, take from that what you will.
And then there is my reference (http://www.reefs.org/library/talklog/d_warren_011898.html) that says this:

"Q :How often can temprature changes in the order of +-2 degree's occur before it starts to have effects on the tanks inhabitants... as a general rule. Personally, I don't think that such a variation in the daily temperature has too much effect on the health of a reef tank.... but there are some previsors on this statement... the tank has to be healthy in all other ways, otherwise the additional stress the occurs due to the temperature fluctuations will take their toll, and cause some problems. I can say that my tank is currently fluctuating through 2.0 ^o C per day with the summer period. And none of the corals or fish, or any of the other inhabitants are showing any ill effects. And if you look at the data I presented, such variations are not out of place on a natural reef. But if you conditions in the tank are substandard, then the additional stress will be a problem. And that is why most people advocate that you minimise the daily temperature variation. Until you really know what you are doing, having the temperature fluctuate may just cause you further problems."

He's erring on the side of caution, which is understandable and common in hobby advice. I agree, it probably doesn't have much effect on the health of the aquarium, so why not have fluctuation within a known "good" ranhe to better equip for corals to deal with thermal stress if a problem does occur.

And take a look at this page:
Pacific Ocean: Great Barrier Reef: Sea Water Temperature Compared to Long Term Averages
the graphs show daily water temps moving a few degrees over a few days at several reefs in the Great Barrier Reef.

It's been shown and proven that temperature changes as much as half of the yearly variation can occur from minute to minute on a typical coral reef. The readings provided by aims are taken coarsely and then averaged out for the day. So, it's not going to show short term and quick fluctuations.

See my reply in orange...

 

[Ron Reefman]

It's been shown and proven that temperature changes as much as half of the yearly variation can occur from minute to minute on a typical coral reef. The readings provided by aims are taken coarsely and then averaged out for the day. So, it's not going to show short term and quick fluctuations.

All I ask Ike is for you to show me any real evidence that, "temperature changes as much as half of the yearly variation can occur from minute to minute on a typical coral reef" I'm not disagreeing that temperature can change, but I think you are WAY over stating the case. Especially when it comes to a "typical reef".

 

[Ike]

So first you assert that... "Over the course of a year the water temp on a reef may vary by 10 degrees (from 75 to 85 in the Florida Keys) but it doesn't go up or down by a degree in any 24 hour period." Now you're refuting minute by minute now that you've realized your original claim is totally false? I'll post this for the benefit of others and because I actually have evidence to back up my claims outside of emphatic claims of ridiculousness and bubble bursting...


This is from Greenbean from Reef Central and other forums, he is a marine biologist with a wealth of knowldege on temperature any coral reefs... Sadly thishis particular thread was part of a now defunct forum. I believe this may have even been in relation to the aims water temperature graphs. Hopefully he doesn't mind me quoting him.

"Myth -The temperature on reefs is stable

Not by a long shot. A typical reef varies at least 3-8 degrees per day with some varying as much as 15. Because these were only measured over fairly coarse time periods, it's likely that short-period changes that occurred quickly were missed. These are not slow changes occurring as the sun heats the water either. In fact it has been noted that the minute-to-minute variation is frequently as much as half of the yearly variation. The origin of these fluctuations are shifting currents, tides, and internal waves. As a result, variation actually increases with depth, contrary to what most hobbyists might imagine."

I think I've supported my argument rather well. If you still don't agree with what I've provided please feel free to do your own research and provide evidence to refute what I have to say.

Thanks

 

[Ron Reefman]

A quote from 'Greenbean' at RC is your evidence? Seriously? Tell me you're kidding, please. He is a marine biologist with a wealth of knowledge and we get to know him only as Greenbean. What is he, some kind of super hero and we don't get to know his real identity... or is he a government secret agent? You have to do way better than Greenbean at RC in order to sell your story Ike. Sorry. Greenbean... your kidding right?

I'll tell you what Ike, you believe what you want to believe and I'll believe what I want to believe. But then I do snorkel and dive on reefs in 5 different countries and 2 different states. But then you can quote Greenbean. We can call this discussion done.

 

[Ike]

A quote from 'Greenbean' at RC is your evidence? Seriously? Tell me you're kidding, please. He is a marine biologist with a wealth of knowledge and we get to know him only as Greenbean. What is he, some kind of super hero and we don't get to know his real identity... or is he a government secret agent? You have to do way better than Greenbean at RC in order to sell your story Ike. Sorry. Greenbean... your kidding right?

I'll tell you what Ike, you believe what you want to believe and I'll believe what I want to believe. But then I do snorkel and dive on reefs in 5 different countries and 2 different states. But then you can quote Greenbean. We can call this discussion done.

What I'm saying doesn't require a belief system. I don't know how to explain it more clearly, but I've actually provided evidence for my argument. You however insist on bashing and asking us to believe in Ron Reefman because he's gone diving and snorkeling... But I quote a marine biologist, one that a lot of the people on this forum know of and respect, and you have a fit. I know Greenbean's real name, but I'm not going to throw it up on a forum since there is a reason why people use nicknames on forums.

The information I'm presenting is supported within the scientific community, it's not some wacky belief like 'the temperature won't fluctuate more than one degree in a 24 hour period on a reef'. I'm not going to dig through more articles and studies so I can prove something I already know to you. Why don't you prove me wrong? Oh wait, you can't...

 

[Albertastorm]

Ron if you have dove...like you said you have? You would have experienced that change in temperature that Greenbean is talking about.
I don't think i have ever dove without experiencing a current coming along that feels like 10 degrees colder! Dive computer has recorded as much as a 8 degree temperature change in the blink of an eye.
Dug up this old thread while searching for the ideal temperature of my reef tank!
I believe warmer is better..keep mine at 81 and fluctuates .25 degrees between heater on and off.

 

[JCM]

Wow, this is an old thread. Hopefully that nonsensical view of "temp stability is crucial" is long gone...