Just transplanted these gal about 4 days ago, vegged in 4x4 rockwool blocks until about 8" tall, then placed in 5" square pots with hydro-rocks. Using H&G Aqua Flakes at about 1500ppm with 150ml of CalMag per 40 gallon reservoir. Flooded them up to the rockwool all was well until I noticed this on a few plants, not widespread but def. happening. Ideas? Rockwool is still a bit wet, but that wont' be a problem as I will not really soak the wool again with my floods. The plants are 64 per 4x4 table under a 1kw with CO2 and perfect climate from a mini split.
Cheers
Cheers