to cover my lights or not to cover...

djyox · 01-23-2005, 07:47 AM

I have hear both ways about this. I dunno what would work out better. I am thinking it would help with the heat off of the 2x250MH bulbs, but what do I use to cover them?

I am using a PFO hood that has a slot for a cover, but I don't know if I should cover them, that I should just go to Homedepot and get some acrylic from them and slide it in?

What do you all think?

Spridle · 01-23-2005, 08:34 AM

If you are talking about putting the acrylic between the lights and the water, I would research further since I believe acrylic/glass absorbs part of the light spectum which would not be good for maintaining corals.

djyox · 01-23-2005, 09:46 AM

yes I am talking about that.

I have read that on forums as well, but also read that you should cover the lights....???

ReefLuvR · 01-23-2005, 11:18 AM

I would be careful about putting any acrylic too close to MH bulbs. Melting plastic would worry me.

Jen

Jeremiah · 01-23-2005, 11:24 AM

I would not put anything between the water and the bulbs.. it is going to block light like someone mentioned and also is going to get dirty quickly and be one more thing to clean on a daily basis...

If you are worried about head I would get some fans in there.

Unless they are DE's I believe you need to have some glass in front of them to block uv light that could harm you and your corals.

clownfishcrazy · 01-23-2005, 01:18 PM

SE don't need glass in front of them, but DE do.

Jeremiah · 01-23-2005, 01:24 PM

Quote:

Originally Posted by clownfishcrazy

SE don't need glass in front of them, but DE do.

Just wondering if this is because SE's are enclosed inside of a uv protected bulb?

clownfishcrazy · 01-23-2005, 03:32 PM

I think that most SE bulbs have a UV sheild on the bulb

David Grigor · 01-23-2005, 04:02 PM

Believe it or not, glass will do the opposite. The heat from the bulbs easily penetrate the glass and actually traps the heat. Even worse on a sumpless system because the water has no where to really go to help cool down like a sump would but still can be an issue on both types of systems.

Only time I would say use glass is if you have notorious jumping fish such as some wrasses and firefish and not using a canopy where you can completely cover any openings. Or if your evaporating too much water causing condensation on your windows, other than those two you really shouldn't cover.

You don't want to use acrylic not really from a light penetration issue but mostly from a warping issue. Acrylic tanks the top really doesn't warp much becuase it has some pressure on it but just a cover will warp very quickly.

djyox · 01-24-2005, 03:54 AM

You mean that I should have condensation on my windows, and ice build up at the bottom of them???

Maybe I should cover....then add more fans...??? Or is there a way to slow down the evap?

Take is always at 80-81. well one time it got to 83.... but mostly 80 sometimes creaps into 81

ofblong · 01-24-2005, 05:05 AM

Quote:

Originally Posted by djyox

You mean that I should have condensation on my windows, and ice build up at the bottom of them???

Maybe I should cover....then add more fans...??? Or is there a way to slow down the evap?

Take is always at 80-81. well one time it got to 83.... but mostly 80 sometimes creaps into 81

evaporation = cooler tank. covered tank = not so much evap and higher temps. uncovered = more evap and cooler temps. hmm if I had hot mh lighting I think I would leave it uncovered unless I had jumping fish where there is no canopy above. if there is a canopy dont worry about covering the acess hoes.

wags · 01-24-2005, 08:48 AM

I think he is talking about using the glass to cover the bulbs that is part of the hood like in this link: http://www.marinedepot.com/md_viewIt...roduct=PF69935
I saw this hood or something close to it on an earlier post from him. The glass slides in underneath the bulbs and would protect them from any water splashes. I have the same hood and the same question. Should I be using that piece of glass to protect the bulbs that came with the hood when I bought it or take it out?

David Grigor · 01-24-2005, 11:11 AM

Wags, like mentioned eariler, If these are regular mogul based ( singe ended ) bulbs then the only real reason to use it is if your light is so close to the water that it could splash. Only other benefit is that it does help the fans pull air from the bulb because your forceing the air to go from one end to the other. With the glass off your not going to get as much air movement inside the hood itself.

Since this a glass over the fixture and not directly over the tank, the glass obviously would do nothing for reducing evaporation or jumping fish. Mostly just to protect the bulb from splashes and to direct the air across the bulbs. With it off the bulbs may run a little hotter and could slightly change the appearance of the bulb because of the bulb temperatures but my experience this is very slight.

I would take it out and only use if you really feel necessary.

wags · 01-24-2005, 12:52 PM

I will defer to your experience and expertise. I have read and heard what you were saying, just wanted to be clear. I am a spec writer by trade and I have a hard time putting that aside sometimes.

Thanks!

djyox · 01-25-2005, 12:39 AM

Wags, that is the hood I was talking about, thanks for the link!

Well I guess I'll get a fan or two more maybe. and leave the glass out....

Thanks everyone for the tips!!