There may be two things wrong too much nutes or a def of some type not really sure bout the def. Are your lights on 24 hrs? Is the humidity 40-50 % Are your foliar feeding dont feed the rockwool cause there is no roots developed yet they get their food from the leaves. Not sure but it could be sulfur def i not sure though just a guess cause sulfer def. the leaves yellow from inside stem out and out in. the rockwool could be too wet. srry for bein late took my g-freind out for a expensive brunch at a five star hotel. It fucken cost 100$ just to walk in and you must be wearing a suit. Alchohal is fuckin expensive too. it was worth it though got some ass.