i personally wouldnt use rockwool in a rain forest!
the system constantly bombards the roots with nutes! if rock wool is kept this wet then it will rot the roots within the block!
skould use growrocs staight away! there are other mediums which include mixes of perlite and growrocs, perlite and hydro soils, coco, not sure about vermiculite!,,but never rockwool!the small cubes will fill the baskets completely and unless there covered from light on top the algae will form on the cube and possibly rot the roots!,,
if you read the info on the rain forest it will tell you all you need to know about using it! GH are forever metioning the disadvantages of using rockwool in this system! so i guess there already in them cubes!,, and the oly thing i can say is, get lots of roots out before you putthem in the system, andmaybe consider putting the motor to run for a few minutes ever couple of hrs or so! as oppossed to continually! saturated rock wool will kill the roots normally! but as the nutes are soo high in oxygen ,,,,,its got me questioning myself!!!,,,,,,,,,,,,let me know how they get on!


welcome to the world of endless possibilities,,,,,hydroponics!