ok, from what ive read, and seen from my cloning exp, the leaves will turn yellow, wilt and die off. its supplying the new roots with food/nutrients while they grow. as long as the stem has nice white root growth, let them be, let them grow, and be patient. my record from cutting to potting is 9 days, and I pulled/potted 15 rooted clones. I also change my cloner machine water every 2 days. and have had excellent success with regent a root rooting hormone at 4ml per gallon of water. and I do ph my cloner water to 6.5. I do have a T8 6500k 2/4' fixture on 24/7.