pH? If you need P or K raise pH to 6.0-6.3. It will also help the ca/mg do it's job. P deficiency usually has purple leaves as it's signature, but it's not to say it isn't happening. If Mother's Finest has had this issue personally, he may be the best advice. You can always add something to give it more vigor, give it things like humic/fulvic acid, carbon, carbohydrates, and silica and they will be happy happy girls.