The Reeflux is pretty blue, more so than some 20k lamps out there. Having said that, we use them (Reeflux 12k), along with some 20k Radiums on a few of the holding tanks we have here, and they work well. The AC's fall off a lot when not being ran on an hqi ballast. They are spec'd to be ran on an hqi, just like the Radium, so if you're not able to do that then I would pass. However, with the Coralvue dimmable, you should have a "250 hqi" setting on it if I'm not mistaken?