Hamilton 14k Metal Halide?

[Andrew]

- Am I getting 420nm using 20000k XM?

If the 14 and 20K's are both full spectrum bulbs, you're still getting some wavelenths in the 420 nm range, just not as much as with straight actinic bulbs.

Andrew

[adamRS80]

Thanks everybody. Now I just have to pay for this expensive bulb. Are there any other options in the 14k range?

[brewercm]

I had switched over to the AB 10K (which is actually 13K) supplemented with actinic VHO and liked the look better than the 20Ks. It appeared to me to make my corals look more natural in their color. Also noticedt that when I switched from magnetic to electric ballast my 10Ks were more blue/white than they were before. I can't say anything about growth since it wasn't that long of a period before tearing the system down, but usually growth is better under brighter light (par rating) which is what you usually get with a lower K rating.
Just my .02 worth.

[Brett Wilson]

Ironically if you want 420nm light from a metal halide bulb guess which one has the MOST, the very yellow Iwasaki 6500K. it's got a TON of yellow, but also a ton of 420nm. It's just overshadowed by the intense and brighter yellow.