Age of plant: Day 43 of flower, day 107 since sprout Lights: 150W HPS, about 2 - 3 inches away Temps: Usually 74 - 78F with lights on, though it has gotten as hot as 86 some days. 55 - 65 with lights off. Soil up 'till 2.5 gallon pot: Mostly coco plus some recycled soil, 1 qt worm castings, plus bone meal, plus perlite. Soil in 5 gal fabric pot (transplanted Day 14 of flower): Monrovia organics (peat based), plus 2 Tbs bone meal Nutrients in flower: Blue Mountain Organics Flower Power (NPK 1-8-7) Flower Power and BMO Super Plant Tonic (NPK 1.25-.4-.9) Super Plant Tonic (I lest fed at about 1/2 strength 4 days ago) Nutrients used in veg: Miragle Gro Orchid food (26-16-12) pH: I don't know. I don't have any meters or testers. I'm not sure if the yellowing started on the bud leaves or the fan leaves. I first noticed it last night on the fan leaves, but with the HPS light I couldn't see it on the bud leaves. I'm attaching pics. Thanks for your help!