With organic fertilizer, unfortunately, it takes a bit of patience. It takes about 3 days for the microorganisms in the soil to process the organic fertilizer and make it available to the plant in the form it needs. You can also fertilize twice a week with 50-70% of the recommendation. This way, you reach 100% of the guideline for a week. This ensures that the plant has a continuous supply of nutrients, and the amount of available nutrients remains consistent.
I would recommend using CalMag once at the beginning of the flowering stage as suggested by BioBizz, and then 50% during the middle of the flowering presentation. Unfortunately, with organic CalMag, it also takes a few days. But that's not a big deal.
Wishing you lots of luck and success 💚🍀