Hey Knally, Hygrozyme is the best, heres what happens, when you first notice and slight browning of the roots pythium is just starting to set in, once you add hygrozyme to roots that are infected, it eats away the pythium, dead/dying roots and sprouts massive new root growth within 3-5 days, now if you werent using it and didnt have problems initially, it may or may not cause some browning and start the phase over again, usually with me i have been using it for 5 months now is it gets real ugly then becomes amazing, but i wouldn't use it like nutes going 1/4 and 1/2 strenght, that stuff needs to be used 8-10ML/gal....saved a whole batch of clones from devestating root rot, but if you have root rot, my advice is to use hygrozyme and change out the rez daily for 5 days, the eaten up roots get nasty and slimier than original root rot and makes the water horrible, and in a week you will have all new roots and any trace of the old roots basically dissolved