there is enough evidence that carbon causes hlle...whether that is true or not.....no clue.
why chance it since you are using it? get rid of it, yesterday...
please use Seachem Purigen for now.
after you have helped your baby back tp health with SELCON and Nori, and you choose to continue to use carbon, use ROX 0.8 by brs.
http://www.bulkreefsupply.com/store/products/carbon-and-gfo/bulk-carbon/rox-0-8-high-performance-carbon">http://www.bulkreefsupply.com/store/products/carbon-and-gfo/bulk-carbon/rox-0-8-high-performance-carbon</a>
here's the article:
[IMG]http://www.advancedaquarist.com/blog/activated-carbon-affirmed-as-causative-agent-for-hlle-disease/">http://www.advancedaquarist.com/blog/activated-carbon-affirmed-as-causative-agent-for-hlle-disease/</a>
whatever you do, make sure that it does not tumble, as no carbon should tumble. ONLY GFO should show a "percolate" at it's serfice.....and that's the best for phosphates by the way...