Not sure many people know about this stuff but I'd sorta forgotten about it until recently. Here is an old thread on RC I had come across a while back. The good news is you can buy it from pool supply stores and is likely not terribly expensive. Not sure of longterm effects I need to take another rip through the thread. I know Joe Y. who runs the amazing 20,000 tank and more at Atlantis Marine World uses it last I heard.
http://www.reefcentral.com/forums/sh...php?p=13390505