Might need chiller-please help

[reefman77]

i was up late last night and i checked the tempature of my tank and it was 85 degrees and my lights had been off for 2 hours!!! my heater is set to keep the tank at 80 degrees. the heater wasnt stuck on or anything. my only cooling is this fan in my canopy (67CFM model) http://www.drsfostersmith.com/produ...&Ntx=mode+matchallpartial&Np=1&pc=1&N=0&Nty=1
i am running 2x 150 watt pheonix metal halide bulbs. over a 120 gallon tank. i am planing to upgrade to the 250 watt version of the same bulb. i also am running a mag 18 return pump with 2 broken impeler blades. do you think the broken impeller is causing more heat in the tank?

my question is, will i be able to keep my tempature at 80 by just using more fans. even if i upgrade to the 250 watt bulbs? if you think i can get away with fans, how many and what type of fans should get?

or do you think I would need to get a chiller? if so what brand and model would you suggest. i want to keep my tempature around 80 but i want good reliabe chiller that isnt to expensive.

the tank is an 120 gallon SPS tank with about 20 gallons of water in the sump.

 

[DarG]

Try fans blowing across the surface of the water in the tank and sump for evaporative cooling. But if you are up to 85 now, going to 250 watt halides may it impossible to keep the water temp. down enough with fans. But definitely worth a try before spemnding on a chiller. Fans will increase evaporation so keep an eye on that. If you need a chiller, do yourself a favor and don't undersize. It may cost a couple hundred more in the behginning to go with a properly sized chiller, but the extra initial expense will eventually pay for itself in electric bill and wear and tear related to longevity of the chiller. An undersized chiller running for 2 or 3 hours or more per cycle will cost you more in electric bill than a properly sized chiller running for under an hour per cycle.

If you find that you need a chiller, the best chiller sizing calculator can be found here ... make sure you take into acount those future lighting upgrades when using the calc. :

http://www.jbjlighting.com/prod_chiller_size.asp

 

[reefman77]

thanks