(12/01/2007) - The Iwasaki 14K(closer to 15K) bulb is a very good bulb. It is a great bulb for growth. If you are looking for a bright white bulb this is the bulb for you. However, if you are looking for a blue 14K that makes the corals "POP", this is not the bulb for you. IMO this bulb needs actinic supplementation for better coral color. This bulb is far brighter than the XM 10K's I had before them and is more pure white, with the XM leaning toward yellow. I was looking to go a little bluer this time around, but the PAR is way too low for the really blue 14K's. Do not let the 4 rating fool you, The bulb would be a 5 in my book if it were a little bluer. I shaved off 1 point due to my preference of asthetics and not because of the quality of the bulb. So, here I go again, round 2 with Iwasaki's!

(10/27/2007) - I've only been using this bulb for one day but it's very intense the same intensity as a 250 watt mh bulb but using less wattage definetly the best 175 watt bulb out there it came with instructions on how to use the bulb and proper positioning of the bulb for proper burn and use,the color of the bulb so far is a bright white looks like a 10k but it actually measures at 14565 kelvin but it doesnt look blue well a hint of blue but not much it doesnt make the colors pop as other 14k bulbs but put a couple of actinics with it and you've got a perfect match i would recommend this bulb to anyone as its definetly worth every penny of it.Very well done Iwasaki keep up the excelent work two thumbs up.

(12/07/2006) - We've had these bulbs over our tank for about a year. Definitely would NOT describe as a warm white, but a screaming bright white with most light/watt according to published data. It provides intense light for growth balanced with a crisp look, but definitely won't make the colors pop as much as some of the bluer bulbs. A good compromise between esthetics and intensity, looks attractive with actinic supp., and the sps have colored well under it.