Here is a photo of what appears to me to be Magnesium deficiency? Hard to tell being color blind. Just have a cpl leaves like this on one plant, and some more like this on one other as well. Leaves are not new growth. I am surprised because I do use RO water. I supplement with Cal Mag plus at 7ml per gal of water using the full compliment of Fox farms nutes following their feeding chart using between 75 to 90 percent of what the char suggests while growing under a combination of LED and HPS. Growing in ProMix ultimate organic with added perlite, vermiculite, and some worm castings. There is a link to my journal in my sig. This is an autoflower plant that is in mid flower. All new growth and the top of the plant looks good.
