i wish people would get off h202, hygrozyume works jsut fine, just the fact that your plants look good shows you that it is working, the roots are feeding from that slime stuff you see on it, it will seem to get worse before it looks better, the bigger root mass you have the quicker your plants will eat the byproduct of the enzymes eating away at the pith....
trust me, jsut stick to the hygrozyme, and add 10ml/gal more every four days until its gone
you don't have to worry about ppm because hygrozyme is like 5-10 ppm, seriously, i just changed my water on sat, i have 14 gallons, i used 200ml hygro, and just this morning i added another 200ml....trust bobby