MH vs. T5HO

I have 2 members in my reef club that have 120G tanks and are running T5HO's on them, one has 8 and one has 10 bulbs. Coral placement is definately a factor with T5HOs, especially on a 2' deep tank. T5HOs drop off significantly around the 14-16" depth. On my 75G with my 1 overdriven MH I can put corals anywhere, actually, not true, I can't put too many corals near the top. Only the super high light corals like Acros do good near the top, most others it is too much light.

For me, I replace ALL my bulbs every 6 months, that is my 1 MH and my 4 T5HO actinics. Reason being, I overdrive ALL my bulbs. Even when I didn't overdrive my bulbs 9 months was my limit. Yes, people say you can run for 12 months before changing, but those same people will read the bottle that Chemi-Pure comes in and swears just because the bottle says you can run it for 6 months that it is true. I replace all my chemi-pure and RowaPhos media every 30 days regardless. I tried replacing bulbs every 12 months but every time around the 9-10month mark a significant algae outbreak would happen due to spectrum change in the bulbs. (could also have been the crappy SunPaq bulbs CurrentUSA sends with their fixtures). Just my personal experience. I am the type of person that would much rather error on the side of caution vs waiting until the breaking point to do something, which may hurt the tank in doing so.

Just some #'s to go by, my 6 24" T5HOs (4-10k/2-Actinic) were putting out around 300PAR, my 1 250w overdriven MH puts out 835PAR. That made a huge difference in coral growth, especially on my SPS corals.
 
With the correct bulbs and quality bulbs you can get very close in par to an average SE MH down to about 18-20 inches depending on the ballast and reflectors you choose for your T-5s. I have gotten 2 years out of daylight bulbs and if you are useing blue bulbs (actinics) just for color then run them till they get to dim or burn out. I know people that have run GE Starcoats for up to 3 years with no problems and that was on an IC Ballast. I can get shimmer lines with T-5's down to about 6-8 inches with daylights and about 4-5 inches with my 2 year old actinics. I would get a top of the line T-5 fixture or do a retro kit because as said its in the reflectors and bulbs. When I first hooked up my T-5's I picked up some SPS's from a guy that had them under MH so I put them up high and bleached them out within 3 days so after that I started them down low then worked them up and everything was fine so you can keep high light SPS's under T-5's and get good color and growth when setup properly.
 
Now we are talking about intensity and spectrum of the bulb right? Sure, a T5HO bulb CAN work for years on end, but how do you know you are getting the spectrum and intensity out of the bulb after 12 months?

I would like to know what combination of T5HOs will give you the same PAR as a single 10K SE XM MH bulb running off of an PFO HQI ballast? Let's see.. if I were to put all 10K 24" T5HOs, which put out a PAR of 70 per bulb on a standard ballast, I would need 12 10K T5HO bulbs to match the PAR of a single MH bulb. I would much rather pay $60 every 6 months vs $300 every 9-12 months on T5HO bulbs. There is no way I could even fit 12 bulbs on my tank, nevermind afford the replacement cost of bulbs. As it is now, I am lucky to have my T5HOs last 6 months, already had 2 UV Super Actinic bulbs burn out within 3 months when being run by a Icecap660 ballast.
 
Since the efficacy of both MH and T-5s are just about the same I keep wondering why folks think MH have more of a "heat" issue.

Both types are equally efficient at taking X watts of electricity and putting out Y lumens of light. This means both have the same amount of heat waste.

If people use less watts of T5s to get the light they want then that would make sense but otherwise it doesn't seem to, to me. Yes a MH seems hotter (is in fact much hotter surface wise) but with both types in identical hoods the same amount of heat should be coming out of the fan outlets. Or am I missing something?
 
Not true, heat is caused by inefficiency of the ballast and light. A T5HO is more effecient in using electricity to make light so it has a little less heat (not much, but it is less). Yes, the electricity consumption in the same if match the wattage, but a MH waste a little more of the electricity than a T5HO does.
 
Ok, show me a post to a REAL site. Sorry, but I really don't consider ReefCentrals "forums" a real site for information. While yes, there is some good info that comes out of there once and a while, most of it is just BS. Still, the numbers in that first link are similar to the numbers I threw out. I was stating 22" bulbs, they are stating 46" bulbs, but PAR readings are similar when size is taken into account.

Now here is a real site for MH outputs.
http://www.cnidarianreef.com/lamps.cfm
and
http://www.reeflightinginfo.arvixe.com/selectperformancedata.php
 
Sorry if this is going off track a little but ACE25 can you show me a REAL site that gives par readings of T-5's I have taken par readings of 2 year old bulbs with minimal drop in par readings I have compared T-5's with 250 watt DE's and came very close to the same readings.
 
Ya, DE are a different story. Real quick point while I go find some T5HO PAR links, don't have those bookmarked anymore.

Best MH:
PFO HQI Dual 250w Ballast w/ 2 10K XM SE Bulbs = 1670PAR

Best T5HO:
2 Icecap660 Ballast w/ 8 46" UV 10K bulbs = 1440PAR (approximate, don't have exact numbers for that in front of me, just going off your link)

So with that information out there, which one is better?
 
How about throwing LED's into the mix?
 
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