There is a lot of debate on that......no the ocean does not stay at the current temperature locally, and tidals experience fluctuations of many degrees a day, and SPS are exposed to air each tidal cycle. Constant with the temperature the same all the time, no, but constant as in a constant cycle, yes. There is an acceptable range for the temp to lie in. Debatable the high and low, but most agree somewhere 74-86 +-. Like alkalinity,salinity, ca....and all the other "stable" params in the ocean, we have found that there is some "wiggle" room to these numbers. If you were driving your temp up to 84 degrees EVERY day then that would be a cycle that would be constant and "stable" so that the coral would adjust and adapt to those constant changes.
Water volume and the internal energy has a direct correlation. Meaning as we all know......smaller tank can bleed off heat faster that larger tanks with fans. One fan on say a 180....won't help much. For your tank volume......will work fine. But the smaller tank also absorbs less heat and the temp rises faster. There are many ways to skin the cat as we all know with this hobby, cooling wise.
There are two points I want to illustrate first.
One. Our tanks our not the ocean and we can not simulate every enviromental param., nor should we attempt to. Take the dissolved nutrients in the water......or things like AEFWs, redbugs, nudis....etc that are part of the ocean. We should remember that our tanks are simplified ecosystems that are missing great BIG pieces of the oceans ecosystems. To compare the two on a one on one basis, would be eroneous......the ocean is the model for our simulations.
Two. These upperlimits are not set in stone, perhaps the livestock you keep can take that high temp once or twice. Perhaps your temp reading was off a little or that fan was just the safety valve you needed? With as much time and money I have invested in my tank, I would never push the limits of any parameter to risk it. What would happen if you had a pump go out then, and the friction from it going bad decreased the mechanical efficiency of the pump,putting more heat into the water and when you are already at your max temperature?
As with our discussion with lighting my mantra is the same,(keeping anenome with PC instead of MH),...sure it can be done, but why push the limit and risk a potential problem or make it harder for oneself? Its hard enough without sabotaging oneself. I try to set all of my params to one setting in the middle of the range and try to keep them as close as possible. If something does go wrong, then I have that safeynet.
Of course, we have to remember I am talking about my SPS tank....my nano doesn't even have a temp gauge on it, because I know the LPS and Softies will take the fluctuations, even with the small volume of water. The SPS tank has two.
SPS is a different breed. Consider the difference in acceptable params of say SW versus FW. I think you would agree the SW params require a narrower range than FW. The same is true with SPS versus softies and even LPS. I have some pieces that if I feed too much one week will turn brown just from that. I took two pieces to John last week that were fine, and now are brown....which I feel horrible about. SPS are VERY sensitive to change. With that said, they don't grow fast or colorful when the params are moving all over the place......its like you and me driving on the street and hitting a lot of redlights.....stop and go, stop and go never getting the chance to open it up and get going......say like on the freeway.......sure your getting somewhere on the surface streets, but the freeway works a whole bunch better.
Being so "finicky" these SPS, and looking toward calculus, think of the SPS as the "limit of the equation" as we push it closer and closer to the "optimal" growing conditions......we are reaching stable and predictible conditions for the animal to thrive. What do you like better? Quiet, calm and predictible or ever changing weather conditions? Which one do you think you would be more productive in?
Long story short.......SPS really stands for Stability Promotes Success.......by pushing the envelope, one not only risks loosing thier corals, but stunts their growth and they never collect enough momentum to grow fast and efficiently.
An excellent example of this very same thing with temp fluctuations and stability is looking at alkalinity......look at someone who doses B-ionic weekly, versus someone who doses constantly with a doser........which corals are going to be bigger?
Nor, do lower the water daily to expose the corals to the air......once in a while if need be is alright.....I just don't do it all the time and risk a problems.
So yes, Edwin....your correct you can fluctuate....but doing EVERYDAY constantly is the best way, not once a year........I just can't afford that risk.....I don't think most people would either........
FWIW, I have about 25 frags/colonies in my tank......retail they probably average about...........$75-$100 each.......all LE or hard too find.....just trying to find them again would be a P.I.T.A. Its that fear of losing them forces me to be vigilant in keeping my params in the middle at all times so when I need it that safety net its there.......
Oh yeah, I got up to 85 once and RTNd about three pieces......that is NOT happening to me again.
In addition looking at it from a probability point of view.....which has more risk, a fluctuating tank with temps and params all over the place, or the freak occasions, when a heater or chiller goes out? By replacing equipment before its life cycle is up, one can greatly diminish those odds. Training ones corals for a fight for thier life daily is not needed.
two words: Redundant systems.....
