Appear stunted 8 days after sprout. Yellowing of leaves, especially the cotyledons. Grayish(?) color on the pic showing the underside of the leaves. Conditions: Grow Tent -- 75F with good circulation Light -- 6500K T5s right on top of them Rockwool temp -- 80F **Humidity -- 15 to 20% **Bought humidifier two days ago that raised levels to 40-45%. I water with RO only when the cubes are almost bone dry. Thoughts?