Down to two lights, looking for assurance...

[midgetwaiter]

Originally Posted by fkshiu

Fluorescent BALLASTS
The Icecap 660 is a very versatile and reliable ballast. It can run T5s if you wanted and in fact will overdrive T5HOs producing more light at the cost of shorter bulb life.

Small note, URI T5 bulbs are properly designated as V-HO. They worked with Icecap to build bulbs that would last longer with their ballasts, provided adequate cooling they last a year.

[fkshiu]

Originally Posted by Whatigot

I had a feeling you might get in on the technical side of this.
Thank you very much for an important set of factors in this decision.
There is a picture of the reflectors on the pfo unit in the picture I attached a couple posts up...
I believe they are the parallel kind?
The xm bulbs have 2 months use and the URI's are brand new.
would I really need to be concerned about enough light for high light corals with either one of these fixtures on a 24' depth?
My 2x150w HQI is giving me good color and I have sps from halfway on up...

PFO parallel reflectors look like this:
http://www.jlaquatics.com/product/pf...Reflector.html

In truth, the PFO unit is probably a bit of overkill for a 24" deep tank like yours, but you'll probably never need to upgrade your lighting again. And the nice thing about PFO ballasts is that you can easily swap the 400w ballast out for, say, a 250w ballast in the future.

The other fixture will probably be fine for your tank if you get quality bulbs and notwithstanding any reliability issues, but there are better be aware that there are better fixtures out there both in terms of build quality, light output and energy efficiency.

The question you have to ask yourself is where you want to go in the LONG run? Do you plan on going all out SPS or mixed? Are you going to upgrade or downsize? How long do you plan on staying in the hobby? For example, if you want to go SPS crazy and plan on staying with a 4'-5' tank for the long haul, a PFO fixture makes more sense. However, if you want a mixed reef and are not sure how long you're going to keep this tank and/or even remain in the hobby, then the eBay one may make more sense.

[fkshiu]

Originally Posted by midgetwaiter

Small note, URI T5 bulbs are properly designated as V-HO. They worked with Icecap to build bulbs that would last longer with their ballasts, provided adequate cooling they last a year.

That is correct! The key is the active cooling , i.e. having fans blowing on the endcaps and bulbs. Having T5HOs in close proximity to high wattage MH bulbs without active cooling can really affect their output/lifespan.