Question about the son agro ballast

[Aquattro]

Bill, yes, that ballast is a HPS ballast. I know of no danger to MH from them, and in fact my regular M59 ballast has a HPS ansi designation as well.
The color on both the 10k and the radium is much whiter than on a M59 or M135. The belief seems to be that the radium bulb will not last as long, although I know of no tests verifying this yet. I suspect it may very well be true, but I am happy enough that the earlier replacement doesn't concern me.
As I think I mentioned before, if at all possible try and view various setups in person to see the color.
Unfortunately in lighting reef aquariums, each reefer has their own different opinion on what is best. RC will have a huge archive of radium/10k/son agro threads, some of which are authored by lighting professionals.