175W MH within 2-3" of the water. Is this to close?

[Anonymous]

I'm going to replace 2-110W VHO's with 2-175W MH 10K. I'll run 2-110W Actinics with the MH's. They will be 2-3" above the water. I'm going to put an acrylic lense on the tank to prevent water splash.

What do you guy's think of this set-up? Will the MH lamps warp or discolor the 1/4" acrylic lense? Will the water temperature go way up? Its currently running between 76 and 78 degrees (with 4-110W VHO's). If the lamps to get a little water on them will they explode? Is MH too hot to touch with you bear hand?

My canopy is only about 6 high, so there is no way to raise the lamps without getting a new canopy.

Opinions please.

Thanks!

my reef

[ February 05, 2002: Message edited by: Louey ]

[ February 05, 2002: Message edited by: Louey ]</p>

 

[eddi]

Louey,

I have a 125 gallon tank with a glass top and a 6' unit with 3 175W MH and 2 7100K actinic sitting right on the glass top without a problem. Of course the unit has a plastic cover at the bottom, so there are two levels between the water and the lights.

My water temperature did increase about 2 degrees so you will need to consider that. I have had this setup for a few months and I have not seen any warping or discoloration. And yes, the lights get too hot to touch!


Eddi

 

[eddi]

Louey,

I have a 125 gallon tank with a glass top and a 6' unit with 3 175W MH and 2 7100K actinic sitting right on the glass top without a problem. Of course the unit has a plastic cover at the bottom, so there are two levels between the water and the lights.

My water temperature did increase about 2 degrees so you will need to consider that. I have had this setup for a few months and I have not seen any warping or discoloration. And yes, the lights get too hot to touch!


Eddi

 

[imow]

I have 2 250's about 3" from the water. Just make sure you have no spray from overflows/pheads/etc. and you will be fine. MH's do get too hot to touch and probably will add some heat to the tank, but nothing which cant be handled with some fans.
The MH will seem significantly hotter than VHO's because they are a point source light.

 

[Anonymous]

Thanks eddi and imow. How often do you have to clean your glass cover?

I'll be setting this up this weekend

 

[Roach]

I have a 400 watt MH sitting about 3" off the glass. There is also a glass cover under the halide as well. I attached to fans to the housing, one blowing in and the other taking hot air out. My temperature didn't seem to go up at all and the glass doesn't even get very warm. I do have to clean the glass once a week or so because the light seems to dry the water out on the glass hood pretty quickly, leaving some film behind. It's nothing too bad though.

 

[imow]

Forgot to tell you my tank has an open top.

 

[AnotherGoldenTeapot]

MH bulbs get very hot - you don't want to touch them.

If you get salt spray on them, even from a fish flicking the surface, then you risk the bulb breaking.

I have 250W bulbs mounted at under 3" above the glass cover on my tank. You need to use tempered glass that close to the bulb as ordinary glass will crack.

 

[MontanaRocknReefer]

Hello! I am having a new canopy made and will house 2 175MH 10,000k and at least 2 110 VHO's actinics and the lights will be at least 9" above the water as there will be no glass top and will have a fan in the hood.
MH bulbs are very hot and never want to touch them! Johnny

 

[louey louey]

teapot-I'm using 1/4" acrylic. It shouldn't crack or melt, should it?