im pretty sure you use both, cause you stick the plants in the rockwhool, and you surround that by the hydroton stuff. the rockwool is kina like the "support", which also is great for holding moisture. and the hydroton keeps moisture.

please any1 correct me if im wrong but thats how i think of it.
PurpWidow Reviewed by PurpWidow on . So confused!! Do I use rockwool or hydroton? okay heres the deal. I hav a little grow space which i plan on growing plants in using a ebb & flow hydroponic system. I am using ebb & flow because a dripper system is too confusing for me & im not sure where to buy a dripper. Here's my question, I know I should use hydroton in the ebb & flow system, but should I also put the plants in rockwool? will the ebb & flow soak the rockwool too much? Rating: 5