MH lights warnings

Davoaldo · 03/22/2008, 07:08 AM

I am currently using T5 for lights and would like to upgrade to MH.

Are there any dangers when using MH lights? ie radiation which will actually damage our eyes or something I am missing. Burn our skins?

Or livestock damage related issue?

I am a little concerned about its safety before I upgrade from T5's.

Sk8r · 03/22/2008, 07:13 AM

Depends on how long you habitually sit exposed to it. It's a lot like sunlight, but you will want a 'light shield' around your rim---some don't, and just hang the lights above the tank, but they are so bright it affects televisions in the evening, etc, and overpowers ambient light. A false 9" rim around your tank [made out of light pine and flexing formica [weighs about 15 lbs for a 54g tank] is a good thing to have in place: keeps the tank from dominating your room.

Glove · 03/22/2008, 07:16 AM

The only thing I am aware of that could cause you trouble is using HQI lighting (double ended metal halide) WITHOUT a piece of glass to filter the UV rays.
It isnt an issue with screw in type lamps because they have an outer shield that acts as the UV filter. Double ended lamps dont have this and need the additional glass.
Aside from heat and high wattages there are no more safety issues using metal halides vs flourescent lamps.

ricks · 03/22/2008, 08:07 AM

MH make me see spots, where t-5 do not.

They do go away in about a year though.

Davoaldo · 03/22/2008, 08:08 AM

This glass bit between the bulbs that filters UV. What if it breaks? How can i replace them? What are these type of glass called?

Agu · 03/22/2008, 08:57 AM

If the UV shield on a single ended MH bulb breaks or cracks you're better off replacing it.

AFAIK any glass will do the trick but if at all possible tempered glass is preferred. It's less likely to break and if it does break you won't have dangerous sharp splinters to clean up.

horwitzs · 03/22/2008, 09:06 AM

They get hot. Recently a member almost had a fire. He posted pics of his hood that was blackened through.
Be very careful about putting them in any kind of hood.

Drix · 03/22/2008, 12:50 PM

I run a dual ended HQI metal halide, the bulb itself comes in its own glass sleeve. Every night I give it a quick once over when I'm putting my tank to bed to be sure it's not cracked.

If it did crack or break I'd just go out and buy a new light. My first MH light I had for 2 years with no problems, now that I know more about light and color I replace my bulb every 6 months, I've still never had a problem.

seapug · 03/22/2008, 01:34 PM

Double ended HQI bulbs should always be UV filtered by a glass plate. They emit a lot of UV and can be very bad for your eyes and livestock. Any well constructed HQI fixture will have the glass platess. Single ended bulbs have a built in UV shield so they do not need to be behind a glass plate, but you really should have something between any MH bulb and the water. If they get splashed they can explode.

george81 · 03/22/2008, 09:10 PM

if you get a proper fixture there is not uv hazard and a proper electrical installation. heat is a huge draw back from MH. in my opinion you re not upgrading from t5ho. the only benefit to MH is the shimmer lines.

Agu · 03/22/2008, 09:13 PM

Quote:

Originally posted by george81
if you get a proper fixture there is not uv hazard and a proper electrical installation. heat is a huge draw back from MH. in my opinion you re not upgrading from t5ho. the only benefit to MH is the shimmer lines.

The shimmer lines are a huge benefit imo.

JimmyS · 03/22/2008, 09:42 PM

They get extremely hot and will burn the begeezers out of you!

cdbias2 · 03/23/2008, 05:08 AM

I use a hamilton Proto with 2-250w HQI's and 2-140w VHO's it has fans built in to the fixture and stays cool to the touch.

Going to this light from PC's I was able to remove my glass tops and it ended up lowering my tank temp by 4 degrees.

Installing any MH without fans is just cutting corners.

I realize what I said is opposite of 99% of the opinions that you will read on this site but it is a fact. Not an opinion.

To clear things up - the fixture has a full glass shield that contains all of the bulbs and the fan air comes in one side and goes out the other, away from the tank.

03/22/2008, 07:08 AM	#1
Davoaldo Registered Member Join Date: Dec 2007 Posts: 177	MH lights warnings I am currently using T5 for lights and would like to upgrade to MH. Are there any dangers when using MH lights? ie radiation which will actually damage our eyes or something I am missing. Burn our skins? Or livestock damage related issue? I am a little concerned about its safety before I upgrade from T5's.

03/22/2008, 07:13 AM	#2
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	Depends on how long you habitually sit exposed to it. It's a lot like sunlight, but you will want a 'light shield' around your rim---some don't, and just hang the lights above the tank, but they are so bright it affects televisions in the evening, etc, and overpowers ambient light. A false 9" rim around your tank [made out of light pine and flexing formica [weighs about 15 lbs for a 54g tank] is a good thing to have in place: keeps the tank from dominating your room. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

03/22/2008, 08:57 AM	#6
Agu Registered Member Join Date: Oct 1999 Location: Sarasota, Florida Posts: 30,279	If the UV shield on a single ended MH bulb breaks or cracks you're better off replacing it. AFAIK any glass will do the trick but if at all possible tempered glass is preferred. It's less likely to break and if it does break you won't have dangerous sharp splinters to clean up. __________________ Less technology , more biology . Current Tank Info: 30 gallon half cube and 5.5, both reef tanks

03/22/2008, 09:06 AM	#7
horwitzs Registered Member Join Date: Dec 2007 Location: Kitsap Penninsula Posts: 470	They get hot. Recently a member almost had a fire. He posted pics of his hood that was blackened through. Be very careful about putting them in any kind of hood. __________________ -Seth Current Tank Info: 120g fresh, 150g salt.

03/22/2008, 01:34 PM	#9
seapug Registered Member Join Date: Dec 2006 Location: 4980 ft. Posts: 7,954 Blog Entries: 1	Double ended HQI bulbs should always be UV filtered by a glass plate. They emit a lot of UV and can be very bad for your eyes and livestock. Any well constructed HQI fixture will have the glass platess. Single ended bulbs have a built in UV shield so they do not need to be behind a glass plate, but you really should have something between any MH bulb and the water. If they get splashed they can explode. __________________ insert clever saying here. Current Tank Info: 200 gallon custom Marineland DD peninsular tank. LPS dominated mixed reef. Previous 90 gallon mixed reef TOTM April 2009.

03/22/2008, 07:16 AM	#3
Glove Registered Member Join Date: Feb 2005 Location: Central Indiana Posts: 562	The only thing I am aware of that could cause you trouble is using HQI lighting (double ended metal halide) WITHOUT a piece of glass to filter the UV rays. It isnt an issue with screw in type lamps because they have an outer shield that acts as the UV filter. Double ended lamps dont have this and need the additional glass. Aside from heat and high wattages there are no more safety issues using metal halides vs flourescent lamps.

03/22/2008, 08:07 AM	#4
ricks Registered Member Join Date: Feb 2003 Location: portland,or Posts: 906	MH make me see spots, where t-5 do not. They do go away in about a year though.

03/22/2008, 08:08 AM	#5
Davoaldo Registered Member Join Date: Dec 2007 Posts: 177	This glass bit between the bulbs that filters UV. What if it breaks? How can i replace them? What are these type of glass called?

03/22/2008, 12:50 PM	#8
Drix Premium Member Join Date: Jan 2005 Location: Massachusetts Posts: 590	I run a dual ended HQI metal halide, the bulb itself comes in its own glass sleeve. Every night I give it a quick once over when I'm putting my tank to bed to be sure it's not cracked. If it did crack or break I'd just go out and buy a new light. My first MH light I had for 2 years with no problems, now that I know more about light and color I replace my bulb every 6 months, I've still never had a problem.

03/22/2008, 09:10 PM	#10
george81 Registered Member Join Date: Jul 2006 Location: canada Posts: 254	if you get a proper fixture there is not uv hazard and a proper electrical installation. heat is a huge draw back from MH. in my opinion you re not upgrading from t5ho. the only benefit to MH is the shimmer lines.

03/22/2008, 09:42 PM	#12
JimmyS Registered Member Join Date: Apr 2004 Location: Edmond, Ok Posts: 743	They get extremely hot and will burn the begeezers out of you! __________________ Jimmy Current Tank Info: 40 Breeder drilled, 20L sump, QuietOne 3000 return, 2 Koralia 1025 evolutions, ~60lbs dry rock, 40lb sand

03/23/2008, 05:08 AM	#13
cdbias2 Appalachian Reef Society Join Date: Mar 2004 Location: Alum Creek, WV (No more) Posts: 1,433	I use a hamilton Proto with 2-250w HQI's and 2-140w VHO's it has fans built in to the fixture and stays cool to the touch. Going to this light from PC's I was able to remove my glass tops and it ended up lowering my tank temp by 4 degrees. Installing any MH without fans is just cutting corners. I realize what I said is opposite of 99% of the opinions that you will read on this site but it is a fact. Not an opinion. To clear things up - the fixture has a full glass shield that contains all of the bulbs and the fan air comes in one side and goes out the other, away from the tank.