HQI Shielding

[discuspro]

Okay, has anyone really really seen a difference between having a HQI unshielded and shielded by glass, or what ever is used to shield? My dilemma is that I have one of those spider-like reflectors used for mogul bulbs in my canopy, but I want to switch to HQI without having an HQI fixture in my canopy.

I know that mogul bulbs are encased by a glass shield, but I'm not sure if HQI bulbs are also incased in UV protective glass or by quartz, which would allow UV to pass.

I really need some one who knows absolutely whether unshielding a HQI would wreak havoc or not.

[alton]

I had posted an article from Coral magazine on this subject with the approval from Coral magazine. Look back to previous pages 8 and 9 in the general reefkeeping forum called UV Shock 1.2.3

[discuspro]

I looked through the article and didn't notice if they had a HQI bulb or Mogul. If it was a mogul bulb than the bulb must have cracked because I have no protective glass in front of my mogul. If it was an HQI then maybe it does require the protective glass. One large mistake they continued to make in the article was that the protective glass was quartz. If indeed it was quartz then the UV, if any was produced, would definitly pass through the "quartz" glass shield. I know that quartz, as a fact and depending on purity, allows partial UV spectrum ranging on through the visible spectrum to pass through it.

On both Mogul and HQI there is a outer glass-like cover that contains the light producing jacket filled with gas. I guess what I need to know is if the HQI outer glass is quartz or not? I'm pretty sure the outer glass of a mogul is not quartz. Lastly, if manufacturers don't use quartz on mogul bulbs then why the heck would they use them on HQI, especially these companies that supposedly make bulbs for aquarium use?

[apedroza]

Ye syou definitely want to put a UV shield over the hqi. The glass around the bulb is not shield, and you could do serious harm to your eyes and your corals after prolonged exposure.

[alton]

Page 86 had a picture of a 150w DE lamp. I had a bad experience with DE lamps, after running them 8 months they lost 50% of there light. So I have switched to SE lamps made for electronic/pulse start ballast.

[caferacermike]

The shield is tempered glass. Having it cut for you is way more expensive than buying this.

http://www.hellolights.com/reflectors.html It's the same price for 150 or 250. I paid $30 a piece for custom tempered glass for a fixture I built. the specs were the same 6x12" that those entire pendants come with.

[discuspro]

That is very cool! They are out of the 250W model, darn it!!

[alton]

I am being told that in the future, DE lamps will have UV protection and not require a glass filter and next year some SE lamps will have a covering that will withstand an explosion.

[Ram_Puppy]

alton, other than the occasional broken shield and UV shock, yours it the first negative thing I have heard about HQI DE's.

can in inquire as to what brand bulb you were using?

I have an icecap electronic ballast running an ushio 10K right now.

[alton]

Coral Vue 14K 250w, then I switched to Ushio 14K and didn't like the color. I have the Ushio sitting in my drawer here at work, I will let them go for $20 each. I have talked to another MAAST member privately and he seems to be having the same problem with DE not lasting as long. Now on the Positive side my SE 12K 175w Reeffux lamps are over 8 months old and haven't lost any foot candles.

[brewercm]

I haven't been a big fan of the Coralvue bulbs. I had the 14K and they looked very dim to me. I do like the hamilton 14K bulbs that I'm using and have had for quite a while now. I've wanted to give the reeflux 12K a try but that's a lot of $$ to find out I don't care for the color/brightness.

[discuspro]

Are you guys talking about HQI bulbs?

[alton]

Coral Vue 14K and Ushio 14K where DE, the 12K 175w are SE, sorry about the slight Hijack

[hobogato]

cliff, come by on the weekend in the middle of the day and you can see the 12k reeflux DE running on my tank.

[matt]

DE bulbs are reputed to last significantly longer than mogule base bulbs when run on an electronic ballast. That's one of their selling points. If you had one go bad after six months, I would guess you either had a bad bulb or it's mismatched to the ballast you were using. HQI is a type of ballast, not bulb, and you can use an HQI ballast on either mogule or DE bulbs. In the case of DE, they typically need either an HQI or electronic ballast to fire. HQI ballasts drive the bulbs a little harder, which increases the light output, but possibly (I've heard stories both ways) shortens the bulb life.

[apedroza]

Actually HQi does refer to the bulb (Hydrargyrum Quartz iodide) which is run by shooting a high electrical voltage through the gas inside the bulb. These bulbs generally perform much better when used wth electronic ballast.