Optimal Temperature

[Street]

I have read a lot of different things on the optimal temperature for our tank. The question arose, because our tank temperature was up to 82 this morning when we woke up (empty at the moment) and that's without our Metal Halide lights!

Our tank setup: (we're ordering liverock/sand today)
Reef tank - 100 gallons
Sump - 40 gallons (3 sections, sectioned off by baffles)
Protein Skimmer
Return Pump
Center refugium in sump

I know that we could purchase a chiller, but since those are very expensive I would obviously like to avoid that! I've read that the upper 70s can stress out indo-pacific fish and that the low 80s can stress out subtropic fish. We're planning on having clowns, tangs, a goby or blenny, some invertebrates, corals, and anemones. (all in due time, of course)

What are you experiences with corals thriving? They are said to do best between 80-85 but those temperatures scare me!

In other words, I feel like all of my fish and corals need different temperatures, and I'm not convinced by any specific one.

 

[Anonymous]

76-80 would be my advice, 85 is way too hot IMO.

 

[Street]

76-80 would be my advice, 85 is way too hot IMO.

Well that's the high range for some fish and corals... this is one of the few articles I read in regards to the temps

Tank Temperatures

And does anyone own Metal Halide lights? How much did they increase your tank temperature? [/url]

 

[Anonymous]

There will be an article about this in the next issue of Reef Hobbyist Magazine.

The issue isn't necessarily what temp you run the tank at. Some people keep their tanks at 82 with no problems. At this time of year, however, temp spiking can be a real issue. Either manual or electronically controlled turning off MH lights (yes they heat the water!) or fans for evap cooling can help keep the tank temp stable.

I like to keep my tank around 78 year round. One or two degree swing either way isn't all that bad.

 

[Anonymous]

I've dived reefs, as I'm sure many others have, where I was downright COLD, easily under 75F. And, I've dived reefs where it was like bathwater, I'm sure well above the 80F mark. Heck, just did several dives in Guam where part of the reef was incredibly warm, and just a few feet over it was significantly cooler.

 

[Street]

I've been trying to find more information on it, it seems that high 70s isn't bad and it actually depends on what the corals original tank temperature was where it was raised how well it will do (or so I've read)

I guess we're going to have to buy a chiller, since our tank is sitting at 80 degrees with no Metal Halide lights or anything. Bleh. They're like 800 bucks!

Has anyone had experience with chillers? What brands or sizes did you buy for what size tank?

 

[Anonymous]

Depending upon the location of the tank you could get away with fans, much more cheaper both in initial purchase and in electrical consumption. The reason why I say depending upon location is they work by evaporation, and depending upon where you are located in the house you might not want gallons of water going into the air

 

[Charlesr1958]

I keep my system at an average of 82 as it is what our corals and fish live within on the reefs, temp swings are also a part of everyday life for the reefs as well and such temp swings are perfectly normal, and would be more concerned if there were no swings. Stable to me equals stagnation, and stagnation in everything is never a good thing. The reefs see such swings every day, some more or less in degree. If I enter the water and am out on the reefs at high tide, I could tell you when the tide is changing by just feeling the "hot" water rushing down the reef from the reef flats that have been cooking under the sun all afternoon and easily reach 90, if not more. But even without such flushing, the lowest temp I have ever recorded on the reef (average 40' deep) is 82, with high averages at 86. Again, the thing about temp is that the corals are acclimated to it, which they need a great deal of time to adjust to. They can easily handle sudden rushes of warmer water for a few hours, but its the long term average temp that will make or break them. Say the reef (or tank) runs at 78 on average, then you flush it with 84 degrees and it cools back down over a few hours back to its 78 average, thats no big deal, but if I were to jump it to 84 and keep it there for a few weeks, I would expect the corals to bleach.

Chuck

 

[Anonymous]

It really depends on the wild reef you are talking about. I have been on some that were 84 and some that were 74.

The damage of sudden temp swings has got a lot to do with o2 levels and flow. Higher temps mean less o2, and if the flow is not so great, less respiration (corals depend on flow for respiration) which can mean unhappy corals. Flow in tanks is dwarfed by flow on wild reefs, which IMO is why wild corals tolerate larger swings in temp.

Your tank could do just fine at 80.

 

[Charlesr1958]

Those tank kept corals that do not tolerate temp swings very well do so simply because they are kept at constant temps which only serves to weaken them.

Please read this article in its entirety.

http://www.ronshimek.com/Temperature%20Salinity.htm

Chuck

 

[Anonymous]

Perhaps I am missing it, but I don't see anything in that mean spirited 'article' about constant temps weakening coral. He presents no evidence at all that lower temps in an aquarium are bad, just evidence that some coral reefs have higher temps than we generally keep at home.
And, like I said above, its not necessarily the temp that does damage, but the lower DO values and respiration issues in tanks that suddenly heat up.

 

[Anonymous]

It's an idea worth considering, though, especially in light of the new research being done in epigenetics. May be a good idea for a thesis if it hasn't really been researched before.

I will say, though, that you're certainly correct about the flow of those very warm reefs. Even if I was able to float and not move an inch (thusly allowing me to watch the two chromis go through their entire mating shebang, and O what a bang it was!), it was very shallow. And where it was warm and deeper, there was definitely more flow. One is an open system where other factors are far more stable, or at the very least optimal for coral and sponge growth, the other (tank), simply isn't.

 

[Charlesr1958]

Theres no arguement that water flow is very important for any reef, but that has little to do with what temperatures the vast majority of our animals have evolved to be in. Unless you have caribbean or Australian corals its a fair bet that your corals and fish come from the indo-pacific region, which just happens to be the center of all reef diversity and has an average year round temp of 82, as you move away from that center, the less species you will find. Since I live within this center and have taken water temp readings at least twice a week for the last four years I can say without a doubt that 82 is the actual average, but on a daily basis it runs from a low (depending on the season) of 80/82 to a high of 84/86, my last reading was about 10 hours ago at 8pm at 40' deep (84F).
With corals and fish being cold blooded they rely upon their surrounding environment for their own body temps, such temps play a huge role in their metabolisms, digestive tracts and immune systems. For any cold blooded animal to be kept in temps much cooler than what they have evolved for can and does have an effect on their long term health, growth and vitality.
Keeping corals at a constant stable temperature also increases their risk because without being subjected to some thermal stresses (changes) they lose the ability to deal with such changes and should your tank have a sudden spike in temp for what ever reason, your corals are much less likely to deal with it. I think of temp changes over the course of a 24 hour period to be much like a work out for the corals, keeping them fit, just as what they experience on the reefs. To keep anything in a stagnant state (stable) is just not healthy at all. That and theres no reason to be so picky or freaked out about keeping a tank at one set temp, a night time low of 80 and a day time high of 84 is perfectly natural and what our pets need for optimal health and growth. That and why waste a ton of electricity trying to keep a tank at artic temps? No need for it.
Oh, and by the way, shortely after the lights on any tank come on, the water will be oxygen saturated and at 84 will hold more than enough for any coral or fish. During the night, an airstone or skimmer or even just the dumping of water through an overflow will maintain sufficient oxygen. Or better yet, run a sump/refugium on an alternate light cycle and never give it a second thought again.

Chuck

 

[Anonymous]

Theres no arguement that water flow is very important for any reef, but that has little to do with what temperatures the vast majority of our animals have evolved to be in.

I don't think I said it did. o2 and flow can play a large role in home tanks because many don't have sufficient flow or o2.

Unless you have caribbean or Australian corals its a fair bet that your corals and fish come from the indo-pacific region, which just happens to be the center of all reef diversity and has an average year round temp of 82, as you move away from that center, the less species you will find.

I think that 82 number is slightly bogus, as it doesn't really account for seasonal temp changes, where it might be 72 for 4 months or 86 for 4 months. It doesn't take into account the huge area that makes up the areas corals in our tanks come from - temps in PI are different than in Tonga.

Since I live within this center and have taken water temp readings at least twice a week for the last four years I can say without a doubt that 82 is the actual average, but on a daily basis it runs from a low (depending on the season) of 80/82 to a high of 84/86, my last reading was about 10 hours ago at 8pm at 40' deep (84F).

Great data for Cebu! And great for natural reefs that have way more flow and DO than home tanks.

With corals and fish being cold blooded they rely upon their surrounding environment for their own body temps, such temps play a huge role in their metabolisms, digestive tracts and immune systems. For any cold blooded animal to be kept in temps much cooler than what they have evolved for can and does have an effect on their long term health, growth and vitality.

That seems to need data to support it, and we need to know what much cooler actually means.

Keeping corals at a constant stable temperature also increases their risk because without being subjected to some thermal stresses (changes) they lose the ability to deal with such changes and should your tank have a sudden spike in temp for what ever reason, your corals are much less likely to deal with it.

I think thats the second time you said that, but do you have any supporting evidence? How much of a temp change over what period are you talking about?

I think of temp changes over the course of a 24 hour period to be much like a work out for the corals, keeping them fit, just as what they experience on the reefs. To keep anything in a stagnant state (stable) is just not healthy at all.

I don't think stagnant and stable are the same thing.

That and theres no reason to be so picky or freaked out about keeping a tank at one set temp, a night time low of 80 and a day time high of 84 is perfectly natural and what our pets need for optimal health and growth.

Again, it depends on where the animal comes from, but sure. At the same time, plenty of aquarists have had animals go down hill from that kind of temp swing. Plenty of aquarists have had great health and growth keeping their tank temps stable.

That and why waste a ton of electricity trying to keep a tank at artic temps? No need for it.

Who said anything about artic temps? 78 is hardly arctic and is well within the range that most corals can thrive. Many people pic 78 because then they don't have to spend money heating their tanks to 80 or 82, and the issue of DO and flow come up because at higher temps there is less DO.

Oh, and by the way, shortely after the lights on any tank come on, the water will be oxygen saturated and at 84 will hold more than enough for any coral or fish. During the night, an airstone or skimmer or even just the dumping of water through an overflow will maintain sufficient oxygen. Or better yet, run a sump/refugium on an alternate light cycle and never give it a second thought again.

What do you mean by oxygen saturated?

I still don't see anything in that 'article' you linked to about constant temps weakening coral, and I am looking forward to understand what you are talking about.

 

[Anonymous]

Much idiotic twaddle has been written, particularly by Charles Delbeek and Richard Harker, about maintaining coral reef animals at lower than natural temperatures...

Heh, I should probably just keep my mouth shut on this one...

Dr. Ron is very good at taking data from the wild and extrapolating it into a controlled captive environment. Charles Delbeek is very good at actually growing corals in captivity. I for one have no confusion about whose opinion to trust.

 

[Charlesr1958]

I don't think I said it did. o2 and flow can play a large role in home tanks because many don't have sufficient flow or o2.

So instead of providing sufficient flow and the means to aerate the water by any number of methods its better to just drop the temp and keep it "stable".

I think that 82 number is slightly bogus, as it doesn't really account for seasonal temp changes, where it might be 72 for 4 months or 86 for 4 months. It doesn't take into account the huge area that makes up the areas corals in our tanks come from - temps in PI are different than in Tonga.

Not bogus at all, it comes from 20 years of data collected by NOAA ocean buoys of which there is a link to within Dr.Ron's article. The 82 temperature stated is the year round average for ALL the reefs in the world. Which means that there are of course reefs that run hotter and some colder. As an example, the red sea runs an average approaching 90! While reefs in Australia can run in the upper 70's. For the Indo-Pacific, that average of 82 just happens to match exactly what the average for all the other reefs combined, which makes sense since the vast majortiy of tropical reefs are found...in the Indo-Pacific, and since its a fair bet (check CITES export numbers) that the majority of corals collected and sold come from Indonesia and the Philippines and that most corals sold do not list their exact collection points with the rare exception recently of aussie corals being sold now. Tonga and other reefs may run cooler, but... why are ALL the species of indo-pacific corals found in Indonesia and the Philippines with fewer species being found in cooler reefs?

Great data for Cebu! And great for natural reefs that have way more flow and DO than home tanks.

Again, it is great data, for any coral that comes from such a biological hot spot.

Peter J. Edmunds Marine Biology 2008 -The effects of temperature on the growth of juvenile scleractinian corals. (They grow better at 82 than at 78 while also having more survive during heat induced bleaching events)

"With corals and fish being cold blooded they rely upon their surrounding environment for their own body temps, such temps play a huge role in their metabolisms, digestive tracts and immune systems. For any cold blooded animal to be kept in temps much cooler than what they have evolved for can and does have an effect on their long term health, growth and vitality. "

That seems to need data to support it, and we need to know what much cooler actually means.

That information has been around far longer than I have and is easily googled. Its like biology 101 stuff. But... it all comes down to what a specific coral has been acclimated to, I am not trying to suggest that 78 is going to kill a coral, what I am suggesting is that a low of 80 and a high of 84 is an acceptable range and nothing to fret about, and.. over the long term it is better for the corals, it is afterall what they evolved to be in. And once again, there is no reef in the world that has "stable" temps, just as you said, there are seasonal (theres only two, hot and dry, wet and cooler) changes, but there are also twice daily changes as well, not only from the sun heating the water but having tidal flows flush out shallow hot water out over the reefs. Which means the corals can wake up to 80 degress and then get hit with 84 to 86 temps suddenely for a few hours before they get flushed with incoming (deeper) cooler water again. Such fairly rapid changes cause no issue with corals. What causes issues with corals is the long term exposure, should those same corals be stuck in 86 degrees for a few weeks, you can bet they would most likely bleach and corals that have been "stable" at one set temp will get hit the hardest. and once again, this information is like old news and am surprised its not better known. (what causes coral bleaching?)

Keeping corals at a constant stable temperature also increases their risk because without being subjected to some thermal stresses (changes) they lose the ability to deal with such changes and should your tank have a sudden spike in temp for what ever reason, your corals are much less likely to deal with it

I think thats the second time you said that, but do you have any supporting evidence? How much of a temp change over what period are you talking about?

A average temp change of 2-4 degrees over a 24 hours period with a few hours of rapidly higher/lower temps within that same period is very common for reefs. As per supporting evidence, not on hand as a published paper yet, but talk to any number of marine biologists and they can explain it, because to be honest, I am just far too dog tired right now to go on a search for papers, three dives yesterday, three dives today and three more tomorrow has this old boy ready for the couch and little thought as possible...lol

I think of temp changes over the course of a 24 hour period to be much like a work out for the corals, keeping them fit, just as what they experience on the reefs. To keep anything in a stagnant state (stable) is just not healthy at all.

I don't think stagnant and stable are the same thing.

Stagnant and Stable both refer to unchanging or idle. There is nothing stable at all about a reef. It faces hourly, daily, seasonal changes in every aspect of it. However, corals have a defined RANGE of tolerances in all aspects of it. Some ranges are preferred over others, hence the variation in coral cover/species amongst the world's reef.

Again, it depends on where the animal comes from, but sure. At the same time, plenty of aquarists have had animals go down hill from that kind of temp swing. Plenty of aquarists have had great health and growth keeping their tank temps stable.

Not argueing that at all, but you have to ask why such animals go downhill when subjected to natural temp swings. To me its simple, the animals are not able to cope with variations when they are not subjected to variations, as they are in the wild.

What do you mean by oxygen saturated?

http://reefkeeping.com/issues/2005-08/eb/index.php

I still don't see anything in that 'article' you linked to about constant temps weakening coral, and I am looking forward to understand what you are talking about.

Believe me, at this point I would love nothing more than to throw up a few links and go hit the couch, but I promise that as soon as I find or come up with something of proof I will post it here. Hope everyone has a great weekend!

Chuck

 

[Charlesr1958]

Dr. Ron is very good at taking data from the wild and extrapolating it into a controlled captive environment

Yeah, heaven forbid we should use data "from the wild" and apply it to our animals that come "from the wild"... :lol:

Chuck

 

[Anonymous]

You know, what you are citing here, Charles, makes sense to me within a larger context. For instance, it is known that certain plants when grown indoors do not develop stems of sufficient strength to hold up growing foliage because they do not get the stress of wind blowing on them (it's much the same for trees that have grown without a snow load on them, it snows hard, and they just snap). The short and pitifully inadequate answer to this is using a fan on them to help strengthen their stems so they can support the growth. I think this might be extrapolated to corals and other organisms rather well.

 

[Anonymous]

Dr. Ron is very good at taking data from the wild and extrapolating it into a controlled captive environment

Yeah, heaven forbid we should use data "from the wild" and apply it to our animals that come "from the wild"... :lol:

Chuck

Well, I didnt know we were going to be misrepresenting each others positions with strawman arguments. Can I try too?

So all animals will behave and react in captivity exactly as they would in the wild?

 

[Anonymous]

I do not see a problem with trying to replecate nature in the aquarium. I keep my tank at 78-80 in the winter and 82-84 in summer. My corals are doing fine, better yet, thriving. Large swings in temperature on a regular basis will cause undue stress.