I always use enzymes after few weeks of growth, insurance really, eats up the dead root matter turns into nutrients. In hydro it's all about the root zone. Insurance is all for me. I use house n garden root excelurator and enzymes. Keeps roots real nice. I am going to use kelp and indole 3...... Instead of root excelurator next grow to see if it's the same shit at a 1/5 of the price ! Indole 3 is the only thing I can think of that does what root excelurator does. Any one have any ideas on this ?