A quote from reefexotics "
ReefLux Metal Halide Bulbs
The Reeflux 10000K has a large spike at 452 nm which is typical of ââ"šÂ¬Ã…"œ20000Kââ"šÂ¬Ã‚ lamps ;but has additional peaks at 534, 588 and 670 nm which has a ââ"šÂ¬Ã…"œwhitening effectââ"šÂ¬Ã‚ on the overall appearance of the lamp.
This combination provides the blue and white spectrum needed for Coral growth, along with eye pleasing whiter light. Overall producing great coloration and improvement of our SPS corals."
I know you were asking about 12k's but I would like to share that I am very happy w/ my reeflux 10k's. I have been using them for 6 months now and I am very happy. I first bought them just because they were cheap. 3 months later they have become very popular locally and I am afraid that their price may go up. My sps love them.