New growth with yellow on the leaf edges is spread...

It does look like a slight over feed though a defiancy in iron will make a plant lighter around the middle in my experience. Nice looking plant anyway as organic has said this is only light she will easily repair and get through that just tone down the nutes a tad next feeding its most likely nitrogen being the main offender usually is :) best of luck pal if you wanted to be sure just flush for few days then reintroduce the feed simple :)