I don't know that I completely agree with that boomer guy. There are other things in that stuff that might work quite well. Lots of people love it.
Personally I think Poly Filters and Seagel is good. HOWEVER: cyano can live in very low nutrient environments so even if you manage to adsorb most of it it may still not get rid of it. Cyano appears to do well in a certain red spectrum light. So if you know your bulbs need replacing why not try that first?

Hey where is corruption anyway?