Leromeanswered grow question an hour ago Hey, my guess would be that this plant in the middle bottom is just more hungry than the others, it appears to be low in sulfur and its definitely having a magnesium deficiency, so give her some epsom salts / magnesium sulfate and see if she gets better.
You can foliar spray it for the quickest results
Foliar spray: dissolve 1 teaspoon of epsom salts / gallon of water and spray that on top of & below all the leaves during night time or with dimmed lights