Metal Halides & Tank Temperature

[NewfieReef]

So I generally try and maintain my tank temperature at 80. I have just upgraded from my 55gal to a 130gal. In the past I ran 4 T-5's over my 55, I got awesome coral growth and the tank looked very nice. (if I say so myself)

So now my 130 is a 4 foot tall tank.... so I put a metal halide fixture over it with two 250W bulbs. The tank is still cycling, I have not moved any fish or coral over, I did purchase a few fish from my LFS to get the cycle started. Tracking my temperatures and I am seeing my temps go from 77.5 (lights off) - 80.5 (lights on)

Now like I say previously with T-5's I did not see any temperature chance. Tank stayed at 80 and was best kind.

Is this a normal temperature fluctuation? Do you consider a normal and acceptable level of temp changes? anything I should be doing?
What temp do you maintain your tank at?

[o2manyfish]

The fluctuation is not to bad. The concern is going to be when summer temp hits do you have a means of keeping the temperature from continuing to rise?

Fans, a chiller, a controller to shut the lights off..... or all 3 to keep things safe.

Dave B

[NewfieReef]

I live in a cool climate so I am not too concerned yet.... I will deferentially be keeping an eye on it......

Looking at buying a controller anyway, was thinking about the Neptune

[FattyK21]

yeah i just had that problem about a week or so ago with my temp getting up to about 83 and some change so i changed my lighting schedule a lil bit and just the other day i took my glass tops off
just doing the tops ive seen a huge change

[Palting]

I have 3 150W MH, with the fishroom ambient temp of 76. Tank temp goes from 78 low up to 81 high in the summer. No issues in over 3 years with SPS dominant reef.

[aandfsoccr04]

I have a four foot tank as well with 2 metal halides over top of it. I see my temps down to the 77 degrees area and up to as high as 81 for the past year and haven't noticed any problems.

[spoonman1979]

Go for the Neptune. I recently got my controller up and running, it is amazing! I have two 250 MH on my 120, the temp definitely rises and get get pretty high depending on the ambient temp. I set the controller to run a sump fan, a larger fan in the room, and shut off the MHs; each at different temp as it rises. I recently had to test this due to an early heat wave and the AC is not yet on in my building. The controller performed flawlessly and I could watch it all from my phone at work. Plus, it helped when I was out of town fir a week and my kalk reactor got plugged, I was able to call a friend to correct the situation.