Pick my MH bulbs for me...

I definitely notice better growth with a 10k. I recently switched from the Iwasaki back to the XM, and the growth is far better. With supplementation, I actually like the color a lot.

 

10k are kinda yellowish and are pron to briopsis

 

I think the algae thing is a bit debatable. It's true some algae can have a competitive advantage under "yellower" light, but 10K is not "yellower" in that regard. You really need to go more like 3K. The reason algae grows under 10K better, is the same reason corals grow better, there is more par. So, if you go with bluer light, say 20K your corals likely won't grow as well, but neither will the algae. If you go with 10K the algae will grow more and the corals will grow more, but the proportion of algae growth to coral growth, should be about the same as under 20K light.

The key words IMO are "competitive advantage". Under very yellow light, such as 3Kish, corals can't utilize the light, but the algae can, so, in this case, the algae grows in a higher proportion than the corals. This is bad, but in the other scenarios, algae growth is really just a sign of excess nutrients. The light is misleading, it's sort of like sweeping the problem under the carpet.

That said, I sort of prefer a bit bluer, so, I am currently running the Phoenix SE 14K. I would say though, it is almost as blue as an XM 20K for example, however, it has nearly twice the PAR of the XM 20K. Which is the real problem with a 20K bulb. To match a 250W 10K with a 20K, you basically need to go to 400W. People like the Phoenix because it splits the difference. Unfortunately though, blue is more popular, so most manufactures tweak their spectrum towards blue. I'm running 4xt-5s as well though, not for par so much, but more for the ability to tweak the spectrum to my liking.

 

I run 4 250w 14K Pheonix and love the color. I have 8 actenics that I am thinking about changing those colors up a little, mixing them up with half the actenics and half more purple bulbs.

I do hear that the whiter bulbs will make things grow faster, however the color will not be as bright. When we set up our frag tank, I plan on getting the whitest bulb possible to get growth and then place them under the DT to color them back up

It is a personal preference though.....Curt likes the more whiter tank, and I like more the blue tank. But he is even happy with the 14k pheonix

If you do decide to go to pheonix I just bought my 4 from aquacave and it was the cheapest I could fine....54 or 59/bulb everywhere around me was 79-110

 

I just got my Phoenix 14k's yesterday. And for the 15 min I had them on, I like the color a lot. I got them from SOS lighting for $48 ea.

 

damn phoenix 14ks are sooo expensive....