Blue Dream 2.0

Week 5 in the bag. All the clones have really shot up and I've trimmed the lower third. Over the past week, they are all showing signs of what I think is a Cal-Mag deficiency. This is odd for 2 reasons. One, they get Cal-Mag with every feeding and two, the mother plant that these clones came from also showed the same leaf problems. The mother plants all strengthened up by the bloom phase but they looked bad for a week until the cal-mag was bumped up. The one plant that is a bag seed from a friend has been on the same feeding schedule and nute amounts and shows no signs of a deficiency. Could this be strain related? Is it not a Cal or Mag deficiency? I'm going to feed water only for the next 5-7 days and see what shakes loose. If anyone happens by and can better diagnose this problem evident on these lower leaves, please leave a comment.