[Q]: max temp

[CrownSushi]

I know the ideal temperature is about 80.
What's the maximum temperature fish and others can endure?

I usually turn off airconditioner when no one is at home.
Then, like today, it will go up like crazy.
Now, I have a fish tank....so should I keep it on all the time?
what temp? 84...85?

[micki]

More importantly is how much does te temp swing?  Tanks can get up to 83 or so safely but becomes more of a problem if the cool temp runs at 80.  1-2 degrees isn't bad over that would be of some concern.

[aquavista99]

I keep my AC on all the time during the warmer months because I use metal halide lighting. Even without halides, I would still keep the AC on all the time during the summer to avoid drastic temperature swings.

Most reefs hit temperatures in the low to mid 80s throughout most tropical regions. Both of my systems go from 79 degrees in the morning up to 82 degrees in the evening with the halides at full blast. Keep in mind the same fluctuations occur in nature (i.e., when the sun goes down, the water temperature drops). I know others who keep very successful SPS reefs with temperatures around 84 degrees. The average temperature for most coral reefs is 82 degrees. The extremes vary from as cold as 61 degrees to as warm as 86 degrees and sometimes higher (i.e., the Caribbean in the summer months hovers around 90 degrees). Corals may bleach if the water temperature exceeds 90 degrees.

Recent trends favor maintaining somewhat more natural reef temperatures of 80 to 84 degrees.