Do they start out like the lower leaves in the first two pics, with the yellowing on the edges? Also, is this first run new ProMix or have you used it before?
They don't look close enough to the fan to be wind damage, and that kind of damage is often potassium-related. Have you slurry-tested the ProMix? Often when weird things are happening all at the same time it's related to the pH of the medium.
They don't look close enough to the fan to be wind damage, and that kind of damage is often potassium-related. Have you slurry-tested the ProMix? Often when weird things are happening all at the same time it's related to the pH of the medium.