What are those yellowish tips?

The N deficiency is my assumption, the spots aren't oxidizing (P deficiency), just the old yellow leaves, there's no diary to check the parameters!, so N is probably affecting K absorption. Check the drainage pH and compare it with the pH you watered with. Increase N uptake if you're using a medium EC soil (1.2 EC) 1.25 ~ 50 ml of BG per liter of water. You're in the flowering phase, so you should start adding BB 1ml per liter of water. If you can check the EC of the previous water products, it will help you know if you have an mg deficiency; you should be able to find information about water quality in your city. Go ahead and see what happens, try adjusting the amount of water for 2-3 days and feed them with each watering.

Burnt straight tips is a sign of potassium deficiency. Seeing as your in flowering. Yes your nutrition level is high as far as the nitrogen goes. Cut back on nitrogen at least half and boost potassium and phosphorus levels. Flowering npk ratio is 1-2-3. Good luck and happy growing 🌱