Looks like a iron deficiency to me, I had a similar issue on my Week 3 of Veg in my diary if you'd like to compare pics. Had it on the Sunset Sherbet and the Tangie. I fixed this with a foliar feed of chelated iron while I got my PH in check. The foliar feed showed results in about a day, but not a permanent fix until you fix the PH. Once the PH issue was resolved, the need for a iron foliar feed was no longer needed.