Leaf veins are yellowing older leaves. New leaves look normal no signs of yellowing. Read the sticky on sick plants and searched web for more info. Answered following questions below. What type of medium; soil or hydro? What brand and type of soil? Indoors or outdoors? What strain? How old are the plants? What type of lights and how many watts? How far from the lights? What is your watering frequency and source of water? What, how much and when was it fed? NPK? What is the medium/runoff pH and PPM if in hydro? What are the temps and humidity in the room? What size pots? Any bugs? Look real close. Any other pertinent info? Soil 18 month old MG garden soil/Potting mix Indoors Papaya 21 days veg + 28 days flower 276/1200 watts CFLs (43/200 watts up top, 86/400 watts middle per plant) 2inchs top, 3+inches middle Tap water every other day Schultz Bloom, 10-54-10 1/2-3/4 strength Never tested medium for pH No humidity check, 80+ F No Bugs Read the sticky and then searched web for vein yellowing and came up with Phosphate poisoning. Mg deficiency was said to cause yellowing leaves while veins remain green. How do you avoid phosphate poisoning when flowering your plants? Phosphorus is what we give the plants to promote flowering. Supposing I should stop with nutrients and find a new source of flowering food. I think I've found what I did wrong and answered my own issue, but would like to get some input anyway. Not much I can do with the current grow with 32-42 days left but flush the soil. Any chance there is something that will make it go away and return the veins back to healthy green?