Hello all,please tell me what is the ideal temp for a 90g I hope to finally set up in July,
I hope to have reef with some softies and maybe a clam or two if I can get the lighting(MH) plus fishies... I have an 16ft large sliding glass doors about 10 ft away from tank that I plan to put window tint on asap to block the sun and then a mini-slpit AC about 10 feet on the other side.(it's kinda blowing right in the direction of the tank) which here in Florida, any ac is good. I decided to go ahead an fill the 90g tank that I have and take temp reading for awhile, after 24hr Im reading about 70*-72* without the lights. My concern is that after I add the lights my temp will go high and I will need a chiller(hopefully not) too much $$$ any thoughts? Thanks!

mr. green

With MH in Flordia, you may be looking at a Chiller. I am sure we have some other Florida people on the board that can tell you for sure. You might just want to start saving for it.


Active Member
My 29g tank with 2 powerheads, a return pump, a skimmer, and pc lighting holds at 80.4 and that's without a heater. My guess is your tank will take longer to heat/cool but you generally want to keep your temp between 77-84 (give or take) but want to minimize fast swings. Don't buy a chiller until you know that you'll need one. You might be able to get away with a fan blowing across the surface.