Temperature? What do you use and why?

[spsphreak75gal]

http://www.advancedaquarist.com/issues/aug2002/Editorial.htm

 

[Paul B]

My tank runs about 86 degrees most of the time and it often goes into the low 90s in the summer. I never ran a chiller in the 37 years since the tank has been running. When it gets into the 90s I put a gallon jug of ice in the water which lowers the temp about 2 degrees.
Tidepools get hotter than that.

 

[sjames]

I run my system pretty cool in the winter, 75-76, but my sump is in the basement and 2 300w heaters run full time to keep it at that.

My corals dont seem to grow very fast at those temps though. Ive seen an increase in growth already this spring as my temps are getting in the 77-78 range.

 

[FizNid]

My tank stays at 78.4 78.6 without the halides on. With the halides it goes up to 79.9 to 80.4 depending on how hot outside. My heaters had died and I didn't realize it(before I got my digital therm etc) so this is more stable and the corals seem a lot happier now.

 

[NirvanaFan]

I usually don't pay much attention to the temperature in my tank. I haven't seen any change in corals or fish with my temp swings. In the summer, the temps generally go from 78 at night to about 82 or up to 83 during the day.
I think that people try to keep their temperature way to stable. I personally don't see a need for that much stability in temperature.

 

[CoreyK]

Just wanted to say great information greenbean! Thanks for contributing.
Once I began scuba diving I began to doubt that temperature variations (withing natural ranges) caused stress to animals. It varies quite a lot more than you'd think, and can be quite drastic. Evolutionarily speaking, it wouldn't make much sense if animals weren't "built" to handle it.

 

[greenbean36191]

I take issue with several points in that editorial and I wouldn't advise reading too much into it.

From the article:

Based essentially on anecdotal experience many experienced reef keepers like me and Greg Schiemer argue that optimum temperatures in the wild do not translate into optimum closed system reef tank temperatures.

Clearly our tanks are not the same as nature, but the same factors that modulate stress are at work and the physiological responses are still the same. Furthermore, optima and metabolic stress are measured in captivity, not the wild. Those measurements are close to what is predicted based on natural patterns of distribution, growth, and disease, which suggests that the same factors are at work. I'm curious what the author believes makes captive corals more delicate than in the wild and makes microcosm values not applicable to our tanks.

Both Greg and I have observed that temperatures above 82-degrees F too often are associated with outbreaks of what we call RTN (rapid tissue necrosis). I prefer to keep my reef tank temperature in the mid to high seventies despite the fact that Ron Shimek has suggested that reef building corals become dormant at these “low” temperatures.

As someone whose tank regularly exceeded 82 I can't say I've observed the same trend. In fact, my first tank, which was by-the-book and hovered around 78 had much more trouble with RTN than my later tanks, but of course I attribute that to chemistry issues rather than temperature. Such is the value of associating cause and effect via anecdotal evidence. I would argue that the author's preference for temperatures in the upper 70s is the cause of his RTN issues at 82, not the natural limits of the corals or any inherent factors of captivity.

In experiments of disease transmission at differing temperatures it was found that no symptoms appeared after inoculation [P. damicornis] at 20 and 25°C after 20 days (68-77°F), but that 100% of the tested fragments showed disease and died at 27 and 29°C (80.6-84.2°F) after just 16 days (the rate was slightly faster at 29°C than 27°C). It is interesting to compare the photos shown in Fig. 3a-d in this paper and those published in The Reef Aquarium volume two pages 444-445 (Sprung and Delbeek, 1997).

It is gratifying to find, as marine biologists study the diseases of corals, that what reef keepers have observed regarding the relationship of high temperature to RTN in reef tanks may be grounded in experimental fact, both in tanks and in the wild.

WAAAAAAAAAAAAAAY too much is being read into the findings here. In this paper, there were corals collected from two reefs. One included healthy corals collected at ambient temperatures of 85 and the other at 77. 77 is a significant number here because it's about the maximum temperature for the area of the northern Red Sea (about 5 miles from my site) where the group of Pocillopora to be inoculated were collected. The fact that the corals are weakened at 4+ degrees above ambient temperatures isn't surprising in the least and does not support the idea that there is anything magical about the value 82 as the author implies. It's just a significant increase above the norm. In fact, one of the groups of healthy coral groups was collected at 85.

 

[Paul B]

My tank is exactly 82 degrees now, it is the middle of May. This is about as cold as the tank has been in almost 40 years.
I only keep LPS corals which may tolerate heat better but I know they have no problems up to about 92 degrees.