hi TGP

what ph do you use to water your plant?
just out of curiosity what is the ph of your run off?

your ph would have to be below 6.0 to lock out the K but it looks more like N deficiency to me (but don't take my word on it)

here is why i think its an N problem
Marijuana Plant Abuse
your plants look like the first Nitrogen deficient plant picture

do you have a ph lock out chart?
hope she does not get any worse