The only way I will consider halides in the future is in a MH+T5 setup, with the MH being 10,000K. A 10,000K is a much more efficient light source than most any T5. But very few consider this to be a pleasing color, so some sort of supplimentation is often used, or a bluer bulb. Bluer halides lose alot of their output with rare exception. In my own setups, the 6x39wattT5 (2xblue+, 2xaquablue, 2xactinic03... a near color match to the pheonix) kills the pheonix 14,000K 250... and that bulb competes with some 10,000Ks!!! So these 14,000Ks and 20,000Ks can get outdone by T5s easily. Otherwise, Halides and T5s used in combo are a very powerful duo. The blue+ T5 bulbs are perhaps the most efficient bulb for producing 450nm blue peaks... better than any blue halide, better than anything except for perhaps blue LED's.
Rich, I have not heard before that a Iwasaki can outdo a 6 bulb tek. I have a 6 bulb Tek that can outdo a 250wattDE pheonix on a HQI ballast... I dont think an Iwasaki can outdo that.
Also, I would like to point out that there are some huge differences in T5 products (much like with halides). An ATI powermodul that Grim tested had 2x the PAR at the sand as a Tek using the exact same bulbs... and I know my early impressions of T5 were based on a friends 75g with an 8 bulb Tek where half the bulbs were hydroponic bulbs, and the other half were the crappy CoralVue bulbs... so I remained a halide 'die-hard' for some time to come. But after owning T5s myself, my opinion has changed. Im sure that a few people's personal opinions may be subject to their past experiences with less than optimal setups.
