Hi,

I recently installed a DIY MH 500W Light with a fan which blows air across the water surface as recommended within the podcast, however my tank temperature will rise from 26 - 28.5 degrees.

I'm slightly concerned as most articles I have read advise to maintained a specific water temperature.

Is there an acceptable allowance in degree shift when dealing with water temperature .

Thanks

What are you planning on keeping? Temp is based upon the inhabitants. A spike like that isn't always goo but if you plan on keeping a reef then you can move the temp to 79 degrees plus and there might be a swim like that.

Thanks for the reply

I'm slowly working towards a reef tank, I set the light slightly to one side so I can introduce high light dependant corals and lower dependant corals in the areas where my light is not as intense with LR overhangs and cover.

When the light is on the temp peeks at 82 Fahrenheit, at the moment I have no real need to use my MH but im experimenting/planning for the near future.

Is the light in a canopy or free standing? Is there a way to install another fan to pull heat away from the light and your tank? Did you see this article? Reefreaders - The Cooling Fan DIY (http://www.reefreaders.com/content/view/35/1/)

A setup with a DIY 500 watt MH light may very well require a chiller when placed over a 60 gallon tank.

Sorry my mistake my MH is 250w, yesterday I installed a big fan over my sump, so far this has worked and keeps my temp between 26.2 - 26.3

So hopefully I've cracked it :)

Thanks for the help.

Yeah, I was gonna say to do exactly what you did :)

Also, if you don't already, keep the doors to the underside of your tank open (assuming you have a pretty traditional set up, with your sump/fuge in the stand of the tank). That helps a lot for me.

I wouldn't worry about temp swings, just so long as they're not drastic. When everything is off and dark at night my tank ends up around 77 degrees, and right after the halides have been on for their 4 hours every day the temp is usually around 81 or 82. Doesn't seem to matter too much to my corals or fish.

I’ve just recreantly installed my sump to under the stairs; lucky enough the surrounding room is cool.

I was worried about the temp swing, but you’ve made me feel a lot happier :)

just a final thought...with the fans running, your evaporation will increase, so stay on top of FW top-offs. better yet, set up an auto top-off. they make things WAY easier.

just a final thought...with the fans running, your evaporation will increase, so stay on top of FW top-offs. better yet, set up an auto top-off. they make things WAY easier.

Your not kidding, im amazed at how much water I loose via evaporation, especially with the warm weather picking up. :eek:

I utilized to commercial grade refrigeration fans in the TOP of my canopy...I did this to assist the Laws of Thermo-Dynamics...heat rises, and the fans pull it out into the room...I DO however, utilize a fan running directly over the water surface to utilize evaporation as a heat dissipation system. I also use a 1/3 hp chiller and my temp is always 79-80 degrees Farenheit.

I utilized to commercial grade refrigeration fans in the TOP of my canopy...I did this to assist the Laws of Thermo-Dynamics...heat rises, and the fans pull it out into the room...I DO however, utilize a fan running directly over the water surface to utilize evaporation as a heat dissipation system. I also use a 1/3 hp chiller and my temp is always 79-80 degrees Farenheit.

Thats a great idea pulling the heat out with fans, I'm looking to change my Lighting hood as i need to include filters for my DE MH, i i will incorporate your solution (some...how)