I cannot figure out what is going on with three of four of my pink lemonade plants.They are at about 3.5 wks into flower.My biggest girl is doing good and flowering nicely but my other three are having some lack of nutrient,that for life of me I cant seem to figure out.I thought maybe a calcium/magnesium issue,but after some research it seems more like an iron issue.I need some input into what may be going on.This is only my second grow,so I am still a complete noob and want to learn from those that have the experience that I lack.Any help would be appreciated.I have posted a couple of pics.