Can the sun rise twice in one day?

[reefrunner]

I have been dealing with temp issues in my tank. I recently got my 250w 14k MH and as you know, it puts out a good deal of heat. I originally had it on an eight hour cycle, but now....in order to keep the temp in check, I have cut it back to 3.5 hrs in the morning, and 3.5 hrs in the evening. Is it ok to run my light cycle this way? Or would I be better off going to a daily 4 or 5 hr cycle?
My temp is ok with the two daily cycles now. It fluctuates between 82 and 84 degrees. Still a bit warmer than I would like, but much better than the almost 90 degree spike I had when I was running a continuous 8 hrs! And yes I did lose a few corals with that spike.

 

[dmjordan]

i would run a continuous light cycle instead of two seperate ones. put a fan blowing across the water to help cool tank. you might have to have the lights come on earlier in the am while its still cool i the house...maybe 2am to 8 or 10 am.

 

[moneyman]

I have 2 VHOs and 2 MHs. Due to heat issues, my controller cycle the MH about twice during the 6 hour photoperiod. My tank has been doing this for 2 summers now. I call it the cloud feature. Hmmm... If I dose top off during that time, I can call it the rain feature...

 

[reefrunner]

Other opinions?

 

[travis99]

you may want to freeze a 20 soda bottle full of water, and put it in your tank. This may be enough to help keep it cool. Keep two or three so you can always have one in there.

 

[1journeyman]

I would think 2 light periods will mess things up.

 

[zeroc]

i was thinking of making like a heat sink out of marble tiles. make like a tank out of marble tiles, put a power head to flow water into it when the lights come on and a fan to cool the marble. Hey who knows.

 

[earlybird]

I wouldn't light the tank twice in a day. How hot is your water getting, do you have a sump, cover, or fan blowing across the surface somewhere?

 

[rbrockm1]

i would put a fan blowing across the top as some1 else said and would raise the light up lil from the tank. sounds like your just going to have to mess around with it until something works

 

[bigblue69]

Have you thought about using a chiller, this will take care of your heat problem.

 

[reefforbrains]

Same price as a chiller is to buy a better AC for your home.
For tank to hit 90* either tank is small or house is very hot.
Otherwise all great advise above. Frozen soda bottles, fan blowing across surface, run open top if possible.
Might also try raising the lights up a little from where they are to curb the heat transfer.

 

[puffer32]

You need to worry more about the temp being consistant then raising to say 84, and doing 2 light cycles will amke the temp jump up and down to much. i use a strong fan (some cool better then others). My temp can still rise from 80 to 84 over the course of the day, but one slow rise hasn't affected my tank at all. I wouldn't want to do that twice in a day, temp would not be consistant and rise and fall to quickly over the course of the day.

 

[garychef1]

put a small office clip-on fan and aim it at your sump. Works like a charm. You can also blow the air across the tank surface, it will look great but it makes evaporation rates very high. I would aim it at the sump.

 

[topfins-mj]

I say definitley do the fan blowing acrross your light fixture , but in the longterm go for the chiller. I bit the bullet and spent 300 bucks on a used one and I have no more worries. I went away on vacation and came back to a sound tank. Save the cash and do the upgrade. Look around here and maybe someone will be offloading equipment.