help with heat

workout · 08/01/2010, 05:18 AM

I have a 125 gallon 48” long reef aquarium that I am setting back up.

I am going to use 4 t5 actinic bulbs and I have a pfo dual 250 w ballast I would like to use also.

My problem is I have put together an enclosed housing for the lights. (17”x48”x51/4”). I have lined it with mirrored plexi glass and I have a 3 inch fan to pull air through, it looks nice and I would like to be able to use it. I know the heat from the halide bulbs will melt the mirrored plexi glass so was planning on putting a piece of reflective insulation behind each bulb. I just don’t know if I am fighting a losing battle with the heat. Do you think I should scrap my plan and not go with the halides? Are there some halide bulbs that run cooler than others? The one I tested is an off brand. What do you think I can do?

Thank you Reef Central.

das75 · 08/01/2010, 09:25 AM

Lot use MH so wouldn't be placing all the blame on them.

If it's getting hot enough to melt the plexi, I'd be replacing it with proper metal reflector or giving more spacing. Also would have a design that doesn't rely on a fan to prevent your house from burning down.

workout · 08/01/2010, 10:22 AM

I haven't used it yet nor do I plan to use it as long as there is a fire hazard and I agree with your point about relying on a fan to “keep the house from burning down”. I was only looking for some suggestions or alternative lighting options. The t5 bulbs do not seem to get all that hot. Maybe some leds or compacts could replace the halides?

moondoggy4 · 08/01/2010, 03:29 PM

My old canopy on my 120 had two 175 MH 9'' off the water and two 4'' ice cap fans, and kept my temps at 82 in the summer, added two more 3'' fans with a controller and my temps dropped to 78'. PS all fans blew in I also had good ventilation in the back.

grigsy · 08/01/2010, 06:23 PM

Add another fan. One fan for halides isnt normally enough. If you can add a second fan to your system, it would make a big difference. Mount one fan on on end and the second fan at the other end - both facing the same direction. That way, one fan will draw air into your canopy and one will draw air out. I think that will help quite a bit.

Also, instead of plexi glass, try using mirrored finished aluminum. That will reflect better and will not be any issue with the halide heat.

Maybe check with marine depot or custom aquatic. Both generally have that available.

workout · 08/01/2010, 07:05 PM

That’s great advice. Thank you! I think the best thing for me to do from the dollars standpoint is to take the easy road and just go with T5 bulbs. From what little experience I have they don’t seem to get very hot. I can put my hand on the ones I have now. Is that normal or are they weak bulbs? If I do go with the t5’s that would lead me to ask just how many and what kind for a 125 gal? I am thinking at least 6.

08/01/2010, 05:18 AM	#1
workout Registered Member Join Date: Jul 2010 Posts: 22	help with heat I have a 125 gallon 48” long reef aquarium that I am setting back up. I am going to use 4 t5 actinic bulbs and I have a pfo dual 250 w ballast I would like to use also. My problem is I have put together an enclosed housing for the lights. (17”x48”x51/4”). I have lined it with mirrored plexi glass and I have a 3 inch fan to pull air through, it looks nice and I would like to be able to use it. I know the heat from the halide bulbs will melt the mirrored plexi glass so was planning on putting a piece of reflective insulation behind each bulb. I just don’t know if I am fighting a losing battle with the heat. Do you think I should scrap my plan and not go with the halides? Are there some halide bulbs that run cooler than others? The one I tested is an off brand. What do you think I can do? Thank you Reef Central.

08/01/2010, 09:25 AM	#2
das75 Registered Member Join Date: Oct 2002 Location: Edmonton AB Posts: 2,269	Lot use MH so wouldn't be placing all the blame on them. If it's getting hot enough to melt the plexi, I'd be replacing it with proper metal reflector or giving more spacing. Also would have a design that doesn't rely on a fan to prevent your house from burning down. __________________ . Current Tank Info: 145g Starfire display (mixed reef) w/75g basement sump & 20g refugium, Barracuda return, Dart w/OM 4way CL, AI Hydras and Director.

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08/01/2010, 10:22 AM	#3
workout Registered Member Join Date: Jul 2010 Posts: 22	I haven't used it yet nor do I plan to use it as long as there is a fire hazard and I agree with your point about relying on a fan to “keep the house from burning down”. I was only looking for some suggestions or alternative lighting options. The t5 bulbs do not seem to get all that hot. Maybe some leds or compacts could replace the halides?

08/01/2010, 03:29 PM	#4
moondoggy4 Registered Member Join Date: Jan 2007 Location: menifee So cal Posts: 11,042	My old canopy on my 120 had two 175 MH 9'' off the water and two 4'' ice cap fans, and kept my temps at 82 in the summer, added two more 3'' fans with a controller and my temps dropped to 78'. PS all fans blew in I also had good ventilation in the back.

08/01/2010, 06:23 PM	#5
grigsy Registered Member Join Date: Sep 2003 Location: Santa Cruz, CA Posts: 2,307	Add another fan. One fan for halides isnt normally enough. If you can add a second fan to your system, it would make a big difference. Mount one fan on on end and the second fan at the other end - both facing the same direction. That way, one fan will draw air into your canopy and one will draw air out. I think that will help quite a bit. Also, instead of plexi glass, try using mirrored finished aluminum. That will reflect better and will not be any issue with the halide heat. Maybe check with marine depot or custom aquatic. Both generally have that available.

08/01/2010, 07:05 PM	#6
workout Registered Member Join Date: Jul 2010 Posts: 22	That’s great advice. Thank you! I think the best thing for me to do from the dollars standpoint is to take the easy road and just go with T5 bulbs. From what little experience I have they don’t seem to get very hot. I can put my hand on the ones I have now. Is that normal or are they weak bulbs? If I do go with the t5’s that would lead me to ask just how many and what kind for a 125 gal? I am thinking at least 6.