I don't know a thing about the Iwasaki, the bulbs that I have came with my coralife unit and they appeared yellow to start then once they were burned in they are a real blue/white, ... My 400 watt MH is turning yellow though (for my orchids) and my tanks that are close to that are getting good algae growth.

I've got 250W iwasakis and they've always been a bit on the yellow side without actinics. I have 2 40W actinics and I really like the look they add to the yellow. I don't know if I would put VHO on mine though. I think that would make it too blue, but thats just my preference. I would think with that much actinic though, Mason, you should see them pretty white/blue. Mine have been running for just over a year now and I'm gonna try to push them to two and see how it goes. It would be interesting to test them and see how much they have gone downhill though. Most people replace them after a year but I've heard of people pusing them to two. Do you have the "R" bulbs?? The non-R ones are pretty yellow compared to the R ones.

Christy :)

Christy's got a good point about the non "R" bulbs. I had one and couldn't believe how yellow it is compared to the newer "R" bulbs. The 400s are quite a bit more yellow in appearance than the 250s.

Troy or Christy, any idea what the R means?

The "R" is for resistor. The Iwasaki company put these carbon resitors in the bulbs to make them burn whiter for reef keeping. I don't really have much more knowledge than that about them. Christy or Troy can probably elaborate on that one a bit.

Thanks Jack.

Actually, that's more than I knew. The only thing I new was that they were for the aquarium. BTW, I bought new bulbs this past weekend so I'll send you one of the old ones to compare.

Send one over this way Troy. I'm using the non "R" bulbs and I want to try it out :wink:

Interesting. I didn't know there were different Iwasaki bulbs. Where would I look for the "R" on the bulb?

Thanks everyone I will look for that when I'm in the market for new bulbs.