How much can water temperature swings effect SPS corals?

[Slodoc07]

I have a 100 gallon system including sump and DT. I run a 300w heater in the DT and 200w in the sump but depending on how cold it gets at night and how warm it gets during the day my water temp can range from 76-80 degrees. I know that water stability is the #1 priority for growing any coral especially SPS coral, is this temperature swing too drastic? now mind you, it doesn't swing that much daily probably close to 2 degrees from morning to night. I just cant get my temp to stay exactly 78 degrees all day long.

Thank you.

 

[P-Dub]

I have a 100 gallon system including sump and DT. I run a 300w heater in the DT and 200w in the sump but depending on how cold it gets at night and how warm it gets during the day my water temp can range from 76-80 degrees. I know that water stability is the #1 priority for growing any coral especially SPS coral, is this temperature swing too drastic? now mind you, it doesn't swing that much daily probably close to 2 degrees from morning to night. I just cant get my temp to stay exactly 78 degrees all day long.

Thank you.

I wouldn't worry about a 2-4 deg temperature swing too much. It is when you go much higher and/or lower than that for extended periods of time that issues arise. I have witnessed corals exposed fully to air and hot tropical sun for an hour or more at a time and mad temperature swings as currents ebb and flow on the reef with no adverse effects. They have mechanisms to battle these swings in temperature. That is just my anecdotal evidence and my personal experience. Chemical parameters such as alk & calcium and other water chemistry parameters are more important, imho.

 

[joseserrano]

I think its how quickly it happens, as well as the corals tolerance. If they are use to it, no big deal, but if its not, it may RTN/STN due to it. Even bleach if temp goes high enough.

 

[P-Dub]

I think its how quickly it happens, as well as the corals tolerance.

That could very well be true, however, I have been hooked into a natural reef during a shift in currents where the water was all warm and fuzzy one moment and literally there was an appreciable temperature drop of 8 deg or more for the duration of the dive. As well, during tide shifts in the reef flats/shallows, I have experienced the same thing. Ideally, you want stable parameters, temperature being one of those parameters, but I wouldn't stress too much about it in your case. It is the large swings over extended periods of time or a constant temperature climb or fall for extended durations outside of your parameters that will be the killer.

 

[joseserrano]

That could very well be true, however, I have been hooked into a natural reef during a shift in currents where the water was all warm and fuzzy one moment and literally there was an appreciable temperature drop of 8 deg or more for the duration of the dive. As well, during tide shifts in the reef flats/shallows, I have experienced the same thing. Ideally, you want stable parameters, temperature being one of those parameters, but I wouldn't stress too much about it in your case. It is the large swings over extended periods of time or a constant temperature climb or fall for extended durations outside of your parameters that will be the killer.

That goes back to the corals being use to that. If that is where they settled and grew, thats their norm. Bali coral, i think that is the actual name of the mariculture facility has their stuff in very shallow water, and is out of water for a period of time, but they have selected species that can handle/will still thrive under those circumstances. We cannot deny that corals thrive under consistency.

 

[Slodoc07]

I appreciate all the help by everyone. Do any of you experience this with you tank or are you able to maintain a constant 78 degrees?

 

[Silence]

I think good water quality, good lights, and stable parameters are more important than temperature. My tank (SPS dominant) swings in temperature from about 75 in winter to 85 during the summer months. I'm only using Walmart clip on fans to cool off the tank in summer. Also I'm in SoCal, so the ambient room temperature doesn't change much...

 

[Slodoc07]

Good to know! I also live in SoCal, Pismo Beach to be exact so we don’t get extreme weather, hot/cold. You pretty much answered my questions, I appreciate it!!

 

[madweazl]

I appreciate all the help by everyone. Do any of you experience this with you tank or are you able to maintain a constant 78 degrees?

Something like a Ranco or Inkbird controller can help provide a more stable temp and provides a level of insurance in the event of a heater failure. Running off a controller, my fluctuation is only .2°.

 

[Slodoc07]

I like that idea. Can they be ran with an Apex?

 

[EmdeReef]

+1 for investing in a controller. My temp fluctuates about 0.2 using P4

2 degree swing prob won’t cause issues but you never know if something else might go wrong too and then the temp stress gets compounded... every time I travel 3 things go wrong at the same time

 

[madweazl]

I like that idea. Can they be ran with an Apex?

If you have an Apex, just control the heater with that (no need for the Ranco or Inkbird).

 

[lauderdalestunner]

That could very well be true, however, I have been hooked into a natural reef during a shift in currents where the water was all warm and fuzzy one moment and literally there was an appreciable temperature drop of 8 deg or more for the duration of the dive. As well, during tide shifts in the reef flats/shallows, I have experienced the same thing. Ideally, you want stable parameters, temperature being one of those parameters, but I wouldn't stress too much about it in your case. It is the large swings over extended periods of time or a constant temperature climb or fall for extended durations outside of your parameters that will be the killer.

Not to pick at an open wound but what’s your opinion on global warming and bleaching. ? I have my opinion but so does everyone else. Temperature IMO is only a minor one factor of many I believe. Temp PH & nutrients in some type of combination?? but I’m no scientist

 

[EmdeReef]

Not to pick at an open wound but what’s your opinion on global warming and bleaching. ? I have my opinion but so does everyone else. Temperature IMO is only a minor one factor of many I believe. Temp PH & nutrients in some type of combination?? but I’m no scientist

Ocean temperatures fluctuate quite a bit throughout the day, what matters is the average.

Bleaching is driven by temperature swings over time. For example just one degree C (1.8F) increase over 4 weeks resulted in bleaching on the Great Barrier Reef.
Corals do appear more tolerant of lower temps though although they bleach in lower temps (in 2010 cooler waters of ~12F caused bleaching around the Keys.)

Other problems can be caused by nutrients, ph etc.but can certainly compound the stress. When it comes to pH the changes are much slower and we still have a bit of time before ocean acidification progresses enough to cause serious harm to corals.

 

[P-Dub]

Not to pick at an open wound but what’s your opinion on global warming and bleaching. ? I have my opinion but so does everyone else. Temperature IMO is only a minor one factor of many I believe. Temp PH & nutrients in some type of combination?? but I’m no scientist

Temperature, if significant and for an extended duration, is most definitely a strong factor in mass coral bleaching events. I think, however, that you touched on something there as well. During these long-duration stress events, there seem to be little additional studies to determine what, if any, additional factors are in play to cause such mass and wide events. It is plain to see that in combination with unusually high temperatures due to global warming and El Nino why mass bleachings occur. However, what about the other parameters that, when out of whack, further stress corals pushing them over the edge and causing bleaching. I think a more in-depth look at all factors is warranted. Lord help us all as ocean acidification increases, add that to predicted stronger and more prevalent storm events, warming of the oceans, pollution, etc., ... it becomes bleak. In summary, I think that you are right that there are other factors involved besides just temperature, but not in all cases.

 

[uhgster1]

I'm adding an entry in here to serve as a bump to bring this up again because I am experiencing temp swings and was also concerned. I found some awesome info on another forum where the members provided some good science links and discussion . The gist of it was this: daily temp swings are not harmful as long as neither extremes of heat 84+ or cold 70- are reached and are actually beneficial. The attempt to maintain temps within +or - .5 or 1 degree is actually unnatural as rising tides and sun rises and sunsets make the temperature fluctuate anywhere between 5 to 10 degrees daily and sometimes hourly. The biggest point I found was that like plants, coral tends to lose their resiliency in such conditions and are more susceptible to disease. Plants outdoors go through temp and conditional swings on a daily basis and of course thrive, while the same plants kept indoors are immediately stressed if brought outside and exposed to what would be natural conditions outside. If you keep plants you know exactly what I'm talking about. If your coral is used to temp fluctuations it will have a much better chance of survival if an equipment failure occurs. I hope this helps anyone out there chasing numbers, it definitely helped me.

 

[foshizzle]

The plant analogy is very good - I could run 79.5-80F this time of year but

I prefer daily fluctuation of 2 deg. I run 76-80.5 depending on time of year to minimize heater usage. IMHO bad things happen more often and quickly at 81F+​

 

[P-Dub]

The plant analogy is very good - I could run 79.5-80F this time of year but

I prefer daily fluctuation of 2 deg. I run 76-80.5 depending on time of year to minimize heater usage. IMHO bad things happen more often and quickly at 81F+​

I think that you are correct in allowing daily fluctuations of 2 deg as acceptable. Even greater fluctuations shouldn't be harmful. I have to disagree with the blanket assertion that bad things happen more often and quicker with water temperatures greater than 81 F. I think that there should be a caveat or qualifier with that statement. IF your water quality parameters are not within acceptable ranges for extended periods of time resulting in already stressed corals, THEN it is certainly reasonable that bad things happen more often and quicker with temperatures greater than 81F.
I have no way of knowing if that is actually true or not but it sounds more reasonable.
For example, I just returned from a week long dive trip to Palau, awesome BTW, and the average temperatures were reading at 83 F on the outer reefs even at depths of greater than 80 fsw and never lower than 81 F. The inside lagoon temperatures were averaging right around 84-85 F. There were greater fluctuations within that mean temperature due to tide changes and currents, eddies and upwellings, etc. but for the most part, the readings were surprisingly high relative to the generally recommended 78 degrees for our reef aquariums. (The dive computer that I use is a fairly accurate technical dive computer from Shearwater Research and reads within less than .5 deg variance of two other digital thermometers I use for comparison). You might be surprised, given the correct and stable parameters, how well corals can do with elevated sea water temperatures over a given period of time relative to seasonal fluctuations. I think maintaining you water temperature at the observed readings I had year round will stress the corals for certain. I think that the problems begin when temperatures rise above the average high temperatures expected accounting for seasonal fluctuations and your parameters begin to fluctuate or wander beyond recommended specs. Finding a reasonable variance within the seasonal highs and lows for tropical corals and maintaining that temperature is certainly more than reasonable. Currently, I maintain my tank at 80.5 to 81.5 degrees during the summer and ramp down to 79.5 to 80.5 during the winter. I don't even give the tank a second thought if the readings are higher or lower than the set temperature due to my wife loving to crank the AC. I generally use the chiller to cool the tank and have the heater set to go off when the temp falls below 79 F. This still gives me a buffer of more than 2 deg F during any seasonal period relative to observations found in my local tropical waters. If parameters are ever out of whack, I'll get them back in line first before I start changing temperature settings.
BUT, all this is anecdotal. You will have very successful tanks with temperature settings that vary as widely as the people that maintain them. Find what works for you but stress far more about the other parameters before you start stressing about the temperature. Corals are extremely hardy creatures.

 

[FlyPenFly]

A thought that I've been playing around with is simulating the temperature fluctuations with a controller. That is, during 10am to 3pm, see elevated temps of 80F, during other times bring temps down to 75F. This can easily be done even on timers with 2 heaters.... This will help coral build resiliency to fluctuations and who knows, maybe bring out some other biological processes not present in our stagnant systems.

If SPS love chaotic strong current, could possibly the same mechanisms to simulate their natural environment exist?

It would be interesting to see what the temp fluctuations are like in a real thriving reef.

 

[P-Dub]

A thought that I've been playing around with is simulating the temperature fluctuations with a controller. That is, during 10am to 3pm, see elevated temps of 80F, during other times bring temps down to 75F. This can easily be done even on timers with 2 heaters.... This will help coral build resiliency to fluctuations and who knows, maybe bring out some other biological processes not present in our stagnant systems.

If SPS love chaotic strong current, could possibly the same mechanisms to simulate their natural environment exist?

It would be interesting to see what the temp fluctuations are like in a real thriving reef.

I am wondering what the impetus is to have the fluctuations during those times and why such a monumental swing in such a short period of time?

I think that acclimating corals to temperature swings are reasonable and in my experience, this occurs on the reefs in nature already. Generally, the large swings that I have seen are temporary and dependent upon depth and location. Some areas of the reef are susceptible to thermocline shifts during tide changes and wave/surge action but settle back to a mean temperature range. There certainly are seasonal shifts in temperature of 3-5 degrees but this occurs over months. Additionally, the only time that you would see vast temperature and condition swings in nature are moon phase dependent. There are those times of the year that the coral reef will be high and dry for perhaps an hour or more, baking in the tropical sun. These occurrences are not often but are, again, moon and tide phase related. All these naturally occurring temperature swings that the corals generally fare well with are with perfect parameters.
I think a slow and gradual process of increasing the temperatures (read many months) to allow for acclimation to higher overall temperatures under consistently pristine parameters is a reasonable endeavor. Be prepared for some losses, however. Unless you have perfect and perfectly consistent parameters and are willing to accept a certain amount of loss I would not undertake this experiment, personally.