Why stable temperature could actually be bad for your corals

[Bramzor]

We are always talking about trying to replicate natural reefs. But why do we try to force a stable temperature instead and do not take that into account?
Me personally, I'm always trying to tweak temperature so it does follow seasonal temperatures (which is a fluctuation of about 2.5°C over the whole year) which I can get using my controller. But in that month I have a 2°C (4°F) limit. But while searching how much natural reefs could fluctuate during the day, I came across this great article: https://reefs.com/magazine/the-grea...ly temperature variation,as the tide comes in.

Few quotes:

For instance, many corals and other reef organisms can survive and grow long term at temperatures of 74 °F and 84 °F

The degree of daily temperature fluctuation on a reef varies considerably from place to place. On an intermediate depth forereef exposed to oceanic swell and adjacent to deep water, the daily temperature variation is quite small—typically < 1 °F. 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.

So I basically just changed my controller, allowing the heater to create fluctuations that are double the swing as before... So instead of a swing of 2°C (4°F), I'm now allowing my tank to swing 4°C (8°F) and even a bit more during the night.

WDYT? Probably it is better to make the corals in our tanks common to swings in temperature so they are prepared for bigger swings if they would ever occur?

 

[X-37B]

I just go with the daily fluctuations which are 2-3°F. IMO your corals adapt to your environment just like they do in the ocean.
Picking a range for all your parameters and keeping them stable and within that range has always worked for me.
Same for temp.
In an enclosed environment a smaller swing in temp is preffered imo.

 

[GabeM]

My darn inkbird swings like a pendulum + or - 1 degree all the time no issues so far

 

[ca1ore]

Lots of things are more constant in our reef tanks than on natural reefs. Not just temperature, but light and flow levels also. Question is whether animals are adapted to withstand such variations or actually need them to thrive. Plenty of awesome reef tanks that don’t bother to program in naturally occurring variations ..... that’s good enough for me.

 

[fcmatt]

I guess i am way too old school and never went all in on a huge tank with dozens and dozens of pieces of coral. I am happy just keeping things alive and in good shape for years at a time. I do not really dig into temp more then a glance at a cheap thermometer and make sure I am right around 78 or 79.. maybe reality is 77 or 80 because it is cheap but that is good enough. Critters look ok.

Now alk is a whole nother story. That beast!

 

[Copingwithpods]

Although replicating nature is great it isn't always ideal. Yes corals can tolorate temperature swings but we avoid it to keep them as stress free as possible. A stressed coral in our tank is much more likely to die than a stressed coral in the wild. We have to baby them where we can so they may survive the things we have no control over.

There are many unknowns in this hobby like why can't some people keep certain corals alive when all other live stock does great? Why do our sps extend their polyps during the day when in the wild they don't? Why do experts struggle with certain species even though they keep NSW levels? Why do some zoas melt away and die while their neighbors thrive?

My point is stable temperature is just a way of giving them the best fighting chance possible. We as humans can adjust to blazing 120 degree Las Vegas strip temperatures as well as freezing Montana winter temperatures, then why do we keep our homes in the mid 70's? For comfort. Which is all we are trying to provide to these animals far from home, comfort.

 

[ZipAdeeZoa]

This is a very interesting question philosophically (to me any way). I've always been involved in keeping various animals and in the beginning I was taught that replicating nature was the best way to insure an animals health. However the fundamentals of keeping animals in captivity have shifted considerably since then and know we know that life is struggle- every animal is out there fighting for their lives day in and day out. Predators, disease and natural disasters test the endurance of these animals and only the toughest get to pass on their genes. The shift from survive to thrive has been a very interesting prospect to me in all my animal hobbies and I'm excited to see how it continues to develop.

My stance has shifted as I've grown and learnt. I think that in nature animals are surviving and millions of years of evolution has made them very good at it. However it is a struggle for survival and these creatures are constantly stress tested to insure only the strongest survive. I think the least we can do for these animals in captivity is insure that as long as we can help it we limit and prevent such stressors wherever possible and focus on helping them thrive- not just survive.

 

[Seneca]

I let my tank swing 74 to about 82 (heat turns off at 78, halides take it the rest of the way). I always figured it would be better to adapt everything to a wider range in case control isnt always perfect.

 

[Reefer1978]

I've been thinking along the same line this morning and want to revive this conversation a bit. Animal life is used to the planets winter <> summer swings. Are we doing more harm by keeping the temperatures stable? I was looking at some temp charts in Great Barrier Reef and some regions have an annual 5-degree Centigrade swing. Some animals use the weather patterns to procreate. In freshwater fish, Cherry Barb for example, we learned that a stream of cold water is what makes them make babies, and it's a currently used technique in aqua culture.