I'm not sure what rockwool should be PH'd to, but did you presoak the rockwool at all before you used it?

It also kinda looks like the stem is rotting at the base. Maybe your water wasn't penetrating the center with the spray, but it looks as though the top stayed really soggy.
irydyum Reviewed by irydyum on . I am a failed horticulturalist. By the way, cloning is impossible. I cut this on the 2nd. I think its experiencing pure misery. Please, can someone help me identify the problem? Notes: 17 days old; Satori 80* in room, 40% RH Mild GH 3-part Sitting on a heat mat Rating: 5