Thanks for your replies.
I allowed the tray to become dry over night and sure enough the root tips underneath have dried out. So I have to keep them moist it would seem.

Floyd, I have considered leaving a layer of solution in the tray, and covering it up with hydroton, which is a great idea, however Blubear makes a good point by saying excess moisture will cause root rot. I have Rhizotonic in the mix, which helps break down old roots and stops the growth of vertain fungus etc, but I don't like the idea of a constantly wet medium. Because of the capilarry water up take of the rockwool, leaving water in the tray will always be sucked up into the rockwool.

Bluebear I plan to keep them in the rockwool, and put them into a pot with rockwool already in it, like a soil transplant. So all the growth now is good.

I guess I'll have to just wait it out and see, it is too early to throw them into a pot just yet imo, so I guess a small % of the roots will die while the rest catch up. I don't want to transplant until there is a large amount of roots, for the simple reason that if i transplant now, the roots will shoot down again, and there will be areas above that don't develop as much as id like.

Any other ideas?
Jkrustie Reviewed by Jkrustie on . Rockwool grow questions Heya This is my first serious attempt with growing soiless in rockwool. I've got some nice Diablo(Next Generation Seeds) seedlings in my 4"x4" rockwool blocks. Growth looks good, and after 5 days going from the 1" cubes to the 4", the roots are starting to come through the bottom. This is where I have a question, how long can you allow the roots to grow through the rockwool cube? I have them in a cloning tray, so the roots will presumptually grow in the tray, sucking up run off Rating: 5