Well I don't use rockwool any more because I find it to be to inconsistent, and after moist to dry and any other kind of enviro change it gets weird.

P.S. god damit locnar you must have got on right before me
socialistpete Reviewed by socialistpete on . Can rockwool melt!? and no, not by fire :) Acidity. The hydro shop owner said if I have a PH of 5.5 or below, my 4-inch rockwell cubes will start melting and shrinking...constricting my plants...therefore...killing them. Any truth? Rating: 5