Metal Halide question

[rplank]

I just got a 250x3 MH fixture. I think I am going to retrofit it into a canopy with only 2 of the 3 bulbs over my 75 AIO. Anywho.....I am reading about MH needing splash guards for protection from the water as well as protecting coral from excess UV radiation. My research seems to indicate that I need special Lexan lenses or glass with UV shielding properties. Is there something commonly (reasonably cheaply) available for this?

This is research I have found, and appears to be well researched and well written: http://www.aquarium-design.com/reef/uvlighting.html

 

[DyM]

HQI, double ended need the shield. single ended mongle bulbs do not. I don't know where you can buy this, hopefully someone had to buy or replace one can chime in.

 

[rplank]

Ok. Mine are hqi's.

 

[scotty b]

I have a couple hm domes that have a clear panel on then, might be uv resistant idk are 9'' around

 

[jda123]

I have just used regular tempered glass from the glass store for replacements. It needs to be tempered.

If you look at a chart from a mogul-based metal halide, they let plenty of UVA through and next to no UVB. You could write a manufacturer and see if they use a special glass on their SE bulbs.

Contrary to that article, I think that you want some UV in the 350-400 range for coloration and pigmentation in the coral. ...or course, too much could be bad. This is a huge miss in LED, IMO. There is a ton in 14K Phoenix, 20K Radium and even more in a 6.5K or 10K lamp.

 

[Skrappy]

Did the HQI fixture you just got not come with glass shielding? I turned a 4' 2 bulb 150w HQI into a 3', just used the same glass it came with for when I did mine.

 

[rplank]

One pane is missing of the three

 

[Miah2bzy]

If u just need one I have one u can have from the 4' that I parted out. I'll let u know wen I come down to Denver this week.

 

[rplank]

Not sure if i need more glass at this point Jeremiah, but thanks. I was pondering covering most of the top of the aquarium with glass but i may just diy some housings and use the two shields I have and leave it open top. I was curious about the shielding properties for if i used the 3rd fixture or ever need to replace another shield or make a top.

 

[Miah2bzy]

Ooohhhh. Gotcha.