Alright, trying to catch this before it gets worse. My Fem'd Green O's just developed some yellow spots within the past 9 hours... They are 9 days young under 400w HPS situated about 24" above. My temp is running around 86-88 with 35% humidity with a nice breeze from an 8" fan. No fertz, just using 2/3 Organic MG for the bottom soil and the top 1/3 is Scotts Premium Potting Soil. I've looked at just about all the pics I can find with no luck in diagnosis since mine are so young. I'm assuming it's just some minor heat stress. Took some precautions by raising lamp height to 28-29" and making air flow more direct to the seedlings. Any thoughts?
Not being scientific but I would point to the soil. Check your runoff PH, also being so young they probably would have been better off being put into something more inert, Im sure that Monisanto dirt is probably too hot for a baby.