Have you considered putting a couple fans in the canopy?

Yeah I thought about that. I'm more interested in even light distribution and if I used a 6 bulb 54 watt T5 setup it might be worth it on power savings but maybe 6 bulbs wouldn't be enough.

i read a study somewhere and when they tested different mh lights and ballasts most used huge ammounts of energy when starting up and while running,electronic ballasts ran at proper levels but i dont think the starting up was any better,im thinking of buying a kill-a-watt so i can test things myself and know for shure instead of just guessing all the time.
i have no proof myself but i would shure assume any mh light system is gonna use a heck of alot more power than a t5 of similar wattage

Mike, how wide is your tank? Could you get an 8-bulb unit?

i say add a 3rd 250w with some t5s aninics or fji purples if thier is room.
if i had a 24" tall tank or shorter i think id keep the t5's i bought but im not satisfied with what i see from my corals, it would be good if someone had a lux meter and a par meter so we could test a bunch of set ups and actually have some numbers to judge things from instead of the same old argument.
i know i have other things to spend $500 on right now though,

heres a lilttle read about par even though its just about mh's

The tank is 24 in wide. I've thought about adding a third pendent in the middle. It would be nice to get rid of those super hot ballasts in my stand rather than add another one though. Maybe I should save up and buy a MH T5 combo unit. I'm due to buy new bulbs for my current set up and I need a new capacitor for one of the ballasts so I figured if I was going to make the change now is the time.

watts is a measure of power so there is no way 100w of mh could be more than 100w of T5... 100w is 100w of power, and yes there is a surge of power when a coil and core ballast is first turned on but its only for a very short time and wont increase your overall power consumption noticibly as it only lasts a fraction of a second.
a kilo watt meter wont show you a startup spike a sits too fast to see, you can make your own wattmeter with 2 multi meters by attaching a ammeter in series with the ballast and a voltmeter in parallel then multiply the values together gives you watts
Amps X Volts = Watts.

Sort of true. Most magnetic ballasts have a pretty awful efficiency factor and will end up drawing as much as 20% more power than they are rated at in normal use.

book i was readin said tar type ballasts use 20-30% more while electronic are almost perfect

using that 48" fixture on your 60" tank will give you a lot of shadow on the sides but it's dooable. There's a guy on RC that tested T5's with a PAR meter going all the way down his 24" tank. Someone else compared his results to another person's test of 250W MH 10k lighting at 24" and the T5's were about 10-20% brighter. That was with a fixture running 50% 10k's, 25% 14k's and 25% actinics.

With T5 you open up the flourescing ballgame though. Anyone seen those flourescent tanks? they look pretty cool :).

As for the electronic vs. tar ballast debate, a 250W electronic ballast will draw only 250W while the TAR will draw like 300W. the TAR ballast will output 300W of light however, while the electronic outputs 250W.

Some people go the whole mile and pair specific bulbs with specific ballasts because you'll get different colour temperatures out of them. Especially for the 400W bulbs.