Indoor Spectrum King closet case and cfl

Recently all my sativa dominate strains are going through a deficiency. I'm not sure if its nutrient lock out from bad ph levels or if I've actually been feeding them to much. I'm thinking it's a ph issue because it dosent look like like normal nutrient burn as you can see in the pictures.( They have only had a few light feedings) But either way I've been only feeding plain water this week. I'm going to get some ph drops to test my ph and see how far off my ph pen is. I'm also gonna be getting some spackling and seal off some of the cracks in the walls of the closet I'm going to be using for bud stage.