i got one of the iwasaki aqua2 bulbs to try out. i have it set up over a 30g (36x12x16), same as a 20g high but longer. this is just a temporary set up before i move though, which is why i only got one to try out.
one thing is for sure, the bulb is VERY bright. I cant imagine the bulb by itself though, without actinic supplementation. i am supplementing with 220w of super actinic URI VHO.
if you like zoas/lps stuff that gives off a good flouresence, you might not be too pleased with the color results from your corals with this bulb by itself. it is less than flattering for most of my zoas.
the XM 10k is much more yellow. i cant see any yellow from the iwasaki, it is pure white. although, after i put it in, it definitely showed off any diatoms/algae on the glass and other areas.
i'm sure the people who love the white look, and not the "bluer" looks, would love this bulb (i.e. sps people, or people with deep tanks). i kinda favor the more blue looks myself, but not too much blue as that tends to wash out alot of color.
very impressive bulb though. i look forward to seeing growth/color results in a month or so. hopefully it will make the sps go crazy.
its all personal preference. you just gota try stuff to see if you like it. then when you find something you like, just stick with it.
