Down to two lights, looking for assurance...

[Whatigot]

Originally Posted by fkshiu

Well let's break things down on a strictly technical basis:

MH BALLASTS
You should be able to get more light out of a 400W electronic ballast vs. a 250W magnetic. It will make a difference if you want to put high light corals and clams on the bottom of your 24" tank (see BULBS below for further discussion on PAR).

Secondly, electronic ballasts will be more reliable in the long term than magnetics and you'll have certainty and consistency of electrical usage with an electronic ballast - it will run 400w regardless whereas 250w magnetics can actually draw up to 300w when in use. On a related note, electronics are also more consistent with respect to output according to Sanjay Joshi's results. There is more of a PAR variation in between different brands of magnetic ballasts so you may end up with either an underperformer or an overperformer. Electronics will also run cooler, are physically smaller and quite a bit lighter in weight than magnetics.

BULBS
Not sure how old the XM and URI bulbs that come with the PFO are, but if they have any life in them left they will be superior to what the other fixture has. Regardless of how happy people are with the actual "cheap Chinese" fixture they buy on e-Bay, there is almost universal dissatisfaction with the no-name bulbs that come with these fixtures. Some reports indicate that the "actinics" in some of these fixtures are just regular bulbs painted blue. You know exactly what you are getting with XMs and URIs Superactinics.

Further, since the PFO is SE and the generic unit is DE, you'll get more PAR out of the SE bulbs simply because the DE unit will require an extra glass UV shield which filters out PAR as well as UV. SE bulbs can be run bare and thus lose less PAR on the way down to the tank.

REFLECTORS
You should find out what type of reflectors the PFO has. They can range anywhere from aluminium to mirror-polished to hammertone. PFO also uses different types of reflectors from the crappy flat type to the better "parallel" style. The reflectors on the Chinese unit are puny and will not give the best spread or most even spread. Reflectors are extremely important in performance. Regardless, neither unit will have very good reflectors in the grand scheme of things - that would go to dedicated MH pendants like Lumenarc or Lumenbright.

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.

OTHER
The PFO is butt ugly unless you like the Mad Max look. Moonlights are neat to have, but can be retrofitted on the PFO. The PFO also may have fans which can be important in the life of T5 bulbs - they tend to give more light and last longer when actively cooled.

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...

[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.