Spring Diesel

Could be the start of phosphorus defiency . I see you have just starting budding which is when it usually shows up . Can also be calcium and phosphorus defiency as they interact with each other . If you feel you are feeding at the correct amounts just make sure your run off PH isn't increasing to much . Around 6.2 to 6.8 is usually optimal , phosphorus is best absorbed by the roots at ph 6.2 in Coco. Your EC looks quite high at this stage , bring it back a bit you don't want to end up with nutrient lockout(check run off EC). Maybe add some calcium to help the uptake of phosphorus . Good luck 🌱