I have been waging a war(and losing) against cyanobacteria until I finally broke down and bought some Chemiclean. It did a really nice job of removing all of the cyano and I now have a nice pretty tank. I have been running GFO in my canister for about a week now. I just started my skimmer back up and changed 20% of the water Sunday. Really, what I want to know is if there are any ill affects that can be expected in the near future as a result from the treatment or is it pretty safe.