Heat and Lighting Questions

[Ichthys]

Ok so today was the first full day with the new lighting. It is 2 Pheonix 14k 250 watt Metal Halides in pendants reflectors suspended about 8 inches above the water and 2 T12 VHO Super Actinics. I came home from work and water temp is 81.5 degrees, I normally run 78. I am a little freaked out, will my fish and corals suffer any harm from the 81.5 temp?
I have 2 Coralife Digital THermometers, they are reading up to 2 degress difference at times. Is there a RELIABLE accurate digital thermometer on the market, something other than an Apex or other Controller based system as I do not have the money for a controller atm.
Are people succesful cooling the tank with only fans blowing across top of water and blowing on MH's or am i going to have to get a chiller? I know chiller would be nice, but once again, money issues... Is it possible to run 500 watts of MH and not raise water temp above 80?
Thanks
Ichthys

 

[Dalbery]

81.5 degrees isn't a big worry. It's more the swings in temp you'll want to watch. Yes fan blowing on the water will help. Your evaporation will definately increase though. The other thing is do you have a/c in your home? If not you will probably need a chiller come summer time. I know that money is tight right now, but maybe you should start putting some money away for a reef keeper lite. They are much more affordable than a lot of people think.

 

[Krish]

The worse part about temperature rising is how fast it comes up. 81.5 isn't bad as suggested. As for fans, they will do a nice job at keeping the temp more stable. You will have to find the sweet spot though. I used 5 fans on my 75gal (3 pulling hot air our of my canopy and 2 pulling cool air in and across the water surface). Worked like a charm for me although I did add a chiller for peace of mind . Also, keep in mind that fans will increase your evaporation rate if it is blowing across the water's surface so you will have to keep an eye on things if you run a sump and don't have an automatic top off

 

[mcoomer]

With the new lighting, you'll probably need to find a way to vent your canopy. On my 125 I had an open back on the canopy and Ice Cap fans at each end pulling air in. On my 180 I've still got the open back and the top is hinged so that I can crack it open to vent warm air out the top. Still, during the day my tank will warm up to just over 80. I see about 1.5 degree change throughout the day, from 78.5 in the morning to just over 80 in the evening.

BTW...post up your thoughts on the Phoenix lamps once they've burned in for a couple weeks. I've been eyeballing one of their 150W lamps to go over my little frag tank.

Mike