Yes. I also have seen great improvement since I've removed it from my system. My tank is still recovering, my SPS hasn't yet returned to the same colours I had before.

If its not iron, it is something and it is linked to the carbon in my mind. It happened right after I put it online, and stopped after I took it out of my system. Either way I'm still thankful for this thread because I probably would have been struggling for weeks or months trying to figure out the cause.

Good to hear that your tank is rebounding Greg.

Chris

+1 And great that you figured it out for everyone, this had (potential) disaster written all over it.

This is not the first time I've heard of weird problems in a tank attributable to carbon. I remember about 6-7 years ago, AJ_77 had a reef tank that the water was continually green, huge huge phytoplankton bloom, nothing he did would cause it to stop getting greener, until he took off his carbon (which was some obscure, presumably cheap brand, which did say on the box "for FW only"). It went away a week after he switched brands.

Did some reading on carbons based on Greg's experiences, in one of the threads discussing it, there was a link to a discussion about carbon available from BRS labelled "ROX 0.8" .. long story short, it sounds really good. I went and ordered two packages for myself already..

ROX 0.8 is great Carbon, I have used it myself. We have access to this carbon as well as lignite which is also almost as good.

I have used the ROX and now only use the Lignite, its what i consider the best carbon available, its a bit pricey but well worth it as you can see in the above posts in this thread.
Cheeper is not always better.

I have a gallon of ROX as well, nice stuff but a lot finer than I expected. Its tough to keep it from clumping. I might try the lignite next time.