Welcome to FC @Charbs32. It looks like a nutrient deficiency, possibly phosphorus.
Is this soil grown in a container or outdoor in the ground? If it's container grown then check the ph off your run off next time you water
You need to adjust your ph down or up into the correct range to allow uptake and flush with 1/4-1/2 strength ferts at an appropriate ph to help bring things into line until you get run off that reads within range.
What ferts have you been using so far?