Tempered glass for MH lens...

[golf nut]

Originally Posted by ner'T'

Anyone know where to find glass for my 250 MH light? I had a thin non-tempered one and surprise-surprise, it cracked from the heat. The lens is approx: 15" x 8.5".

Thanks for any input

You might want to check for something special about the glass, simply replacing it with regular glass that you get tempered may not be that simple.

[mr.wilson]

Originally Posted by Mr OM

You might want to check for something special about the glass, simply replacing it with regular glass that you get tempered may not be that simple.

HQI lamps have a UV filtering quartz outer glass, so you don't need to have a quartz glass lens. You needed a quartz lens with the old Osram Powerstar lamps.

[sphelps]

Originally Posted by mr.wilson

HQI lamps have a UV filtering quartz outer glass, so you don't need to have a quartz glass lens. You needed a quartz lens with the old Osram Powerstar lamps.

I was under the impression the HQI or DE bulbs don't have the UV filtering outer glass and require tempered "low emissivity" glass. It's the Mogul or SE bulbs which have the UV filtering outer glass and don't require any additional requirements for a glass shield.

[fencer]

They can be found in any glass shop ( 20 / pane). Actually DE have the UV filter. The extra glass shield is to protect you from an exploding DE.

[Marlin65]

My Mh have Low E tempered glass on them and are DE.

[sphelps]

Originally Posted by fencer

Actually DE have the UV filter. The extra glass shield is to protect you from an exploding DE.

That doesn't sound right, why would a DE bulb be more likely to explode?

DE lamps do not have the large outer envelope typically found on single-ended lamps that is used to limit the lamp’s UV radiation. Double-ended lamps require an additional safety glass to be installed in the lamp’s fixture in order for them to be safe for your tank’s inhabitants.

http://reefkeeping.com/issues/2007-03/sj/index.php

[fencer]

DE bulbs run under pressure....I can't remeber but I think it was greater than 50 psi

[brizzo]

Speaking from experience cooking everything in my tank ... DE halide bulbs are NOT UV shielded; except the ones from Coralife (or so they claim).

Personally I was unable to find a glass shop that could get a piece of tempered glass that small. Each glass shop I checked with said "no problem, but it's a minimum charge of $30 for any tempered glass", then would get the phone call "sorry we cannot get tempered that small". The explanation was due to the small size of the glass not being able to travel through the furnace that does the tempering.

But, if you do find a shop that is able to produce; please let me know