Opinion on keeping metal halide lamps bare or with a glass cover

[kylemm]

Hey everyone, you guys have been awesome helping me with this new tank build. The only other tank I've owned has been a 29 biocube. So a lot of this i s a first for me.

I bought a nice used 75g with a stand and hood. The tank is still about a month away from being run. However, after mounting the pair of 250w metal halide fixtures into the hood. I realized a potential problem. Due to the hood, the lights can only be mounted about 4-5 inches above the water. They are lumenmax elite pendants. I have become worried about water splashing on the bulbs and potentially causing them to burst. I haven't been able to find the original glass shields for them either. Since they has been discontinued. I thought about putting a lid over the tank. However, I know that would not be good for temps, oxygen exchange, and light. So I thought my other option might be to have a local hardware store cut a few pieces of glass to put below the lamps to shield the bulbs from any splashes. While still leaving open area for evaporation. If it helps, the back of the hood is open so there will be air flow. Also, the back of the stand is open. So the sump will be getting plenty of open air..

Am I right in being concerned with this? Or is this just a novice worrying too much about something that won't matter in the end?

Thank you for your time! Any help would be great!

 

[jrr98002]

I think you're correct in your concern. As far as a solution, what you suggest sounds reasonable. If anyone else has other suggestions I'm sure they'll chime in.

 

[Breadman03]

I'm not very knowledgeable with MH, but I believe that double ended bulbs need glass with UV protective coating whereas single ended don't. I would take the fixture to a local glass shop and see what it would cost to have pieces cut to the proper size.

 

[kylemm]

I'm not very knowledgeable with MH, but I believe that double ended bulbs need glass with UV protective coating whereas single ended don't. I would take the fixture to a local glass shop and see what it would cost to have pieces cut to the proper size.

That's kind of what I was thinking. Its only a SE bulb so the UV isn't a issue. Would I be running into serious heat issues with a lid? If i did do a lid im thinming id be installing fans to blow across the pendants to help carry the hot air away. I have a elite aquatics m2 sump, and it will be a open top. Just to give you a idea of the water volume in sump. My only concern with the custom glass is the removing and installing every time I need to access the tank to clean. Where as a bought lid would be able to be opened and cleaned easier. At least, in my head it would be.

Sorry for the rambling! I just want to make sure I covered everything.

 

[johnike]

A glass shop could cut them for you if you could provide them with dimensions.
I've always run my 5 SE MH with out glass.

 

[A sea K]

I'm not very knowledgeable with MH, but I believe that double ended bulbs need glass with UV protective coating whereas single ended don't. I would take the fixture to a local glass shop and see what it would cost to have pieces cut to the proper size.

Yes, DE bulbs require a shield and SE bulbs do not. However, your concerns of water splash breaking the bulb is also a valid one but with two 250watt bulbs merely 4-5" off the waters surface you are going to have some major heating issues as well.
I would figure a way to raise the fixture within the hood or design a new hood altogether if you have to. It is the best solution to both problems in the long run.

 

[kylemm]

Yes, DE bulbs require a shield and SE bulbs do not. However, your concerns of water splash breaking the bulb is also a valid one but with two 250watt bulbs merely 4-5" off the waters surface you are going to have some major heating issues as well.
I would figure a way to raise the fixture within the hood or design a new hood altogether if you have to. It is the best solution to both problems in the long run.

Okay, well I will take a look and see if I can find any way to raise it. I haven't been able to yet. I am trying to avoid buying a chiller. However, that might be the only way. I didn't think it would be a huge problem. It is I'm the basement, so temps would be the lowest in the house.

 

[tmz]

The double ended bulbs need a uv shield of glass. The single ended mogul types don't. Salt spray is a problem for both.

 

[kylemm]

The double ended bulbs need a uv shield of glass. The single ended mogul types don't. Salt spray is a problem for both.

I understand that. I'm more concerned with temp issues. That's more of what I'm trying to figure out.

 

[tmz]

You mean the potential for bursting? If so, I can say I use moguls over open water on some tanks and they get sprayed a little. Never had one burst but I suppose it's possible. Those are about 9 inches above the water. I also use glass covers on some that are within 5 inches of the water .Those fixtures have vents and fans.

 

[kylemm]

You mean the potential for bursting? If so, I can say I use moguls over open water on some tanks and they get sprayed a little. Never had one burst but I suppose it's possible. Those are about 9 inches above the water. I also use glass covers on some that are within 5 inches of the water .Those fixtures have vents and fans.

Yes sir. That and also if I'm going to have worries with heat. Some say yes, others say with fans it should be okay. I didn't know if a bulb bursting was a serious issue or not. I don't mind cleaning the reflectors now and then. I just don't want a 80 dollar bulb burstingjust because it got splashed with a little water.

 

[kylemm]

You mean the potential for bursting? If so, I can say I use moguls over open water on some tanks and they get sprayed a little. Never had one burst but I suppose it's possible. Those are about 9 inches above the water. I also use glass covers on some that are within 5 inches of the water .Those fixtures have vents and fans.

Also, this is just me throwing it out there. I found a insane deal from a family friend who is thinking of selling a 1hp aqua euro titanium chiller. He wants 250 for it. Would it be completely idiotic to place this on a 75g? Or would it mean it'd take care of any heat issues and wouldn't have to come on often?