MH vs HQI

[stonepilot]

tank will be 18 inches deep, but my real question is which do you feel is better and why. thanks for all help

 

[spaulr]

What I think you mean is SE (Single Ended) vs DE (Double Ended). HQI means Mercury Quartz Iodide, and is a type of bulb which can be both SE or DE. Marketing has used this acronym as a selling point feature, but it is very misleading and confusing .

I've been looking for lighting for weeks now for my LPS tank so I'm hot an bothered about this .

Pros-
Let's take 150w DE. They put out as much or more PAR than their 175W SE brethren with the same electronic ballasts. The DE bulbs also last a few months longer than the SE bulbs. Your long term costs should be less for the same amount of light. Sanjay's site has tons of info on 150DE vs 150SE, same with 250DE and 250SE + various ballasts.

Cons-
Cost is a bit higher for DE due to purchase of a pendant, even for DIY.

 

[Anonymous]

I prefer the double-eneded HQI. The bulbs seem to last longer and put out more light. The downside is a lack of bulb choices.

 

[Unarce]

From what I've learned, double-end bulbs appear to give out more PAR watt for watt because of the bulbs thin diameter. This allows a quality reflector to deflect more light with less restrike, pushing more light downward. The drawback, is that double-end bulbs have a poor spread pattern compared to single-end. A glass shield is also a must have.

This difference in spread may change when PGS comes out with their double-end Lumenarcs this month, but it's not exactly a cheap solution.

 

[spaulr]

Not to hijack the thread...but why will PGS double-end Lumenarcs be $$$$? New technology?

 

[Unarce]

I don't think it'll be much more than the Lumenarc III or Mini. I find that some people have trouble spending $100+ on a reflector or finding enough room in their canopy. It's well worth it IMO.

 

[minibowmatt]

I always thought you needed a E ballast to run HQI? Will Magnetics run them?

 

[Unarce]

It's best to use an HQI or e-ballast. There are magnetic HQI ballasts out there, also. You may be able to fire up the lower kelvin double-end bulbs with a standard ballast, but the higher kelvin ratings will definitely require an HQI or e-ballast.

 

[minibowmatt]

what is different about HQI magnetic ballast internally? is it just the ignitor?

 

[Unarce]

That, I don't know :?