Waiting For 'god'.............

[Aquascaper]

Obviously Superman has all the answers so we'll let him do a post on Lighting..................................

 

[superman]

T6 is also a new option, though it may not be very popular and may not become popular since T5 is taking the market so strongly.

[/quote]MH is generally considered to be the only way to sucessfully keep SPS and clams

This was true about 3 years ago, at wholesalers, aquacultrue facilities (not to mention some of the most successfull reef tanks I have ever seen) VHO and T5 bulbs are even more successful at keeping SPS and clams healthy and growing. I kept a clam under PC for two years (it is now under T5) When considering T5 fluorescent lights it is very important to have a good reflector and a high quality ballast. T5 bulbs when coupled with high quality single bulb reflectors penetrate just as well as most MH. I wouldn't mention this unless this had merit and was something that may need to be corrected in your otherwise pretty good list of information.

 

[SkiFletch]

sticky?

 

[Aquascaper]

T5 bulbs when coupled with high quality single bulb reflectors penetrate just as well as most MH. I wouldn't mention this unless this had merit and was something that may need to be corrected in your otherwise pretty good list of information.

It is claimed that the T5 HO tube is an excellent alternative to Metal Halide bulbs when 8 tubes are used in a hood. This is not always an economic alternative

I feel that pretty much covers it as well as stating that it may not be cost effective to use multiple T5's where a single Halide would do the job. Considering a Twin T5 110w light would cost around £102 for an aftermarket unit (£55 for ballast + tubes @ £16.50 each + reflector @ £6.99 each) and you can pick up a 250w Metal Halide with 10,000k bulb for around £96 it seems to make more sense to go for the halide if you want to keep SPS and clams. The overall point being made is that Metal Halides are the optimum type of light for a Reef tank, that's not to say that there isn't alternatives.

 

[superman]

I don't know where you got the "8 tube" comparison to halide, I would be interested in seeing that study. The numbers in various studies I've read point towards a much less bulb count needed to be equal to or greater than "Metal Halide". For a loose generalization about 3 T5 bulbs (with individual reflectors) are equal a metal halide. So when I bounce the numbers as far as cost up front, cost to run, cost to replace and lifespan, T5 wins hands down, especially in terms of longevity.