No sarcasim intended, Im just shocked that a material project manager would manipulate percentages like that. What it looked like you were saying is almost like telling someone, "Ok, you have a dozen eggs, and want 50% more, here are 6 more for a total of 18"...and then a few seconds later..."Oh, you dont want that 50%? Oh, well let me take that 50% back then", and you take 9 eggs back (9 being 50% of 18 of course)"...um, er, yeah, you are taking away 50%...sure...but you see where you might be misunderstanding the info here?
I retrieved the exact numbers from Grim, so the percentages are no longer off the top of my head... Swapping ballasts on a 54watt bulb, "the IC is good for a reading of about 183 compared to a regular ballast that would make 135 on that same bulb". So, if there were 1.5x that bulb with regular ballast/bulb/reflectors, the PAR would be 203. No more percentages, thats makes me lean to the regular ballasts (triad, advance, fulham, etc) any day. The regular setup is about 10% (percentage from total, not base since that number would be higher) brighter right off the bat...and there is more...
Now, I do agree with you on one thing. If you have limited hood space and you want to eek out more wattage, the Icecap is a good option.
I want to add something else in as well. And BTW, for those looking, geek is not the cheapest place to buy tek lights...I bought mins for half that. Greenhouse suppliers will sell you the unit for $250-$300. Look on ebay, youll see. You brought up bulb replacement costs though...and thats a whole other can of worms. The IC ballast is burning out bulbs faster than normal. The general accepted period of T5 replacement is something like 18-24 months for them (the actinics are the least stable, the days are the most), but icecap users are reporting significant drops in PAR within the first 6 months, and replacement within 12months. So for initial setup cost, sure, the 6 bulb setup needs an extra $40 in bulbs...but over the long run, you will most likely need to replace all your bulbs in 12months vs. 18months. That means that in 3 years (a common denominator), at $20 a bulb, the 6 bulb unit will cost $240 if the bulbs are replaced at 18 months. For the IC, replacing ALL the bulbs every 12months means the same $240 is spent. And along the way, people with IC ballasts are reporting drops in PAR early on (most likely due to the excessive heat which is the only concern for phosphor longevity). Excessive heat, not hard starting, is what burns out our bulbs as far as output goes, and the IC simply makes more of it...burning out bulbs faster. The IC appears to be burning even the daylight bulbs down to 50% of their output in 6 months! Regular ballasts lose about 10%! Now, I am betting that the cooling might not be up to PAR on these calculations, but I would also like to add in that these readings were on 5' bulbs (dhoch's) which on an Icecap only get overdriven by 20watts to 100watts on the IC ballast. Thats not a large boost, but a huge loss in output.
And then there is startup cost. Note: I am leaving the cost of the first 4 bulbs, reflectors, and endcaps out of this since they are a constant that can be negated from the cost of either setup. An IC ballast costs $150-200...lets go with geek for pricing....$169 plus anywhere from en extra $25-50 in harness add-ons and such. Lets just say $200 total. Now, a more expensive T5 ballast, the Triad, is $40 for two 54watt bulbs...so thats $80 for four. Now, thats a pretty pricey ballast considering fulhams are $40 for a 4x54watt unit...but Ill go with it. So for 6 bulbs (comparing the IC w/ 4 bulbs to the regular w/ 6), the triads save you $80 on ballasts alone. Heck, fulhams would save you $120. That $80 can buy 2 bulbs at $20 ea, 2 reflectors at $20 ea, and the only cost extra is the endcaps really...$20 more...which is with the triads...since the fulham setup with the 2 extra bulbs, reflectors, and endcaps would come in at $20 less than the IC setup.
It seems to me that the IC ballast is a bit like M80 ballasts are for halide. Sure, they generate 10-15% more PAR right off the bat, but they overdrive the bulb so much that by the time the usual replacement time comes around they are at 40% of their starting output. (info from a GE lighting engineer) e-ballasts like the IC might not have that edge when they first fire up the bulb, but they are able to maintain the PAR for much longer and in the end have a 30% PAR drop if that so that at the end they outperform the HQI anyways. I wonder if the PAR when using the IC ballasts after 9 months isnt lower than the normally driven kinda like the halides above.
I do have a 660 ballast laying around, and a 4x54watt IC retrofit as well. I might have to hook it up and run it to get some long term test results. Currently I am running an objective test (er, a 'coral's opinion' test...) > given the same water parameters by linking tanks, will a 250wattMH generate more growth over a 40B, or a 6x39wattT5 unit? And with which types of corals (I will have some identical softies, rics, zoas, SPS, LPS, and shrooms in each)? The light spectrum is rather balanced as well...the 250 is a 14,000K pheonix, and the Tek has 2 aquablue, 2 blue+, 2 actinic03...the coloration looks near identical as the tanks are next to each other. The T5 bulbs are new, and when the second 40B is set up, I will swap out the pheonix bulb for a new one since the current one is 8 months old...and I want them to have an equal start. Should be interesting.