I've used Ultralife Red Slime Remover - comes in a package that looks similar to ChemiClean but it's not as volatile, in my experience.
Yes, Cyano does come in green and the Ultralife product has worked for me on it.
As always, the chemical "fix" just treats the symptom, not the cause, so you might want to take a closer look at what might be causing it. Flow is probably not the issue, but somewhere there is a heavier nutrient load than there should be, and that's feeding it.
Jenn