How warm is too warm?

[beatle]

With the recent temperature spike the past couple days, I've kicked my AC on for the first time since I've had my new tank setup with 2x250w halides. I have two clip on fans blowing into the back of my canopy (wish I had a push/pulll setup) to aid in dissipating the heat, but temps still rose to 82. I typically keep the tank @ 79, and the thermostat in summer is around 77-78. Is a 3 degree swing too much? If no, what is too much, and how warm is too warm?

[hypertech]

My BC29 with the metal halide in the hood used to swing about 4 degrees a day up to about 83. It was fine. My tank now swings about 2-2.5 degrees and I expect it may a little more than that when summer comes.

 

The smaller the swing the better, but I think you are fine. As for a max temp, i really try to stay below 83. With this tank in the basement, being too cold is more of an issue now. I started to get worried at about 84 or 85. I've had spikes up to 90 that didn't kill everything but I did have some losses. So, I'm not sure there is a hard cutoff, but I'd start thinking about fans or maybe even a chiller if I saw 83. You may also consider dropping your regular temp to 76 to prevent the spike during the middle of the day from getting so high.

[beatle]

Yeah, I've considered dropping the regular temp, though I can't go much lower than 78 in the summer as ambient temperature will be close to that.

 

I may add an additional fan over my sump. This worked well enough on my 90 w/4x54w T5s and a much shorter canopy, but that was less than half the wattage!

 

I really don't want to deal with the additional plumbing and placement of a chiller. If I thought this was a possibility, I would have just plumbed the sump into the basement.

[hypertech]

In addition to lowering the temp as much as you can and a fan (which can be very effective but be prepared for more evaporation), you can consider a split photo period. Run the main lights in the morning and the late evening and avoid running them in the hottest part of the day.

[lhcorals]

My system runs between 80 and 82. I have 5 250 watt MH, 14 39 watt T-5's and 2 160 watt VHO's. 3 of the 250's, 8 39 watt T-5's, and the 160 watt VHO's run during the day on the display and the other lights run at night in the fish room downstairs. Its a total of approx 550 gallons on the system. I am comfortable with the temps being at 82.

Edited April 26, 2011 by lhcorals

[Incredible Corals]

Glad to hear this. My tank is getting to 81.7 with the heat outside and I was worried it was too high. Haven't had any heat issues with the LEDs until now.

[lhcorals]

Also wanted to add that my house thermostat stays at 69 all year. My basement probably stay a cool 60 in the summer so this helps. I dont run a heater in the winter either and my temp stays 80 to 82.

[Coral Hind]

My tank normally gets to around 83 almost daily in the Summer. At 83.5 the ACIII starts turning the MH lights off but it rarely gets that high. I also decrease the photoperiod by an hour during the Summer. Today the low was 78.2 at 9am and the high was 82.2 at 7pm.

[beatle]

Well this is somewhat of a relief. I'll still keep an eye on the tank, but I don't feel so bad about the temperature rising to 82. Hopefully the temps stay relatively stable throughout the summer.

[Glenn]

A couple posts have mentioned it briefly, but do you have a controller? If not, you could also think about getting one so that if your water temp gets up to 82 then your MH lights will cut off until the water temps drop back down to a better temp. Or, as someone else suggested, use the controller to turn your lights off from (example) noon to 3pm, then back on for some evening hours.

[Fazio92]

I run my tank year round at a constant 83. A few years ago i would get worried if it was in the 78-79 range so i bought a chiller. Honestly, since i have been running at 83 for the past few years, growth and quality of life in the tank seems much greater. Now i just have the chiller turn on at 83.5 and all lights off past 84, but that very rarely happens. As long as there are not signifcant fluctuations day in and day out, i think safe ranges can vary significantly. Just my 2 cents.

 

-Anthony

[magnetic1]

Or split the lights between days. Have one of the MH in the pair turn on one day and off the next.

[treesprite]

I wouldn't want to go above 83. My temp generally stays between 79-81. I don't need to use thermometers or a chiller, but use a couple fans that I turn on or off. Last year when there was that obscene unexpected heat wave, my temp hit 90 and some of my corals suffered... one fan being on would have been enough to keep it survivable temp, but it stopped working on it's own that particular day.

[beatle]

A couple posts have mentioned it briefly, but do you have a controller?

 

I do have an AC3. Part of the reason I started this thread was researching at what temperature to turn my lights off and send an email.

 

I only run my lights from 4pm - 11pm.

 

The staggered photoperiod with one light on and one light off (same day) would be interesting, but I run a dual 250w ballast with one power cord.

[Coral Hind]

What is a safe temp also depends on corals you have and where they came from. Corals from deeper areas or cooler waters like around Tonga might not do as well with the warmer temps. From my year of diving at Guam I know that the water there in the shallow reefs was normally around 82-84F on the West side of the island. The East was always just a few degrees cooler because of currents.