What are these little spots?

https://www.biobizz.com/wp-content/uploads/2024/04/Nutrient-Schedule-EN-2024.pdf Following the feeding guide and then adjust the concentration to your needs. Keep he ratios but diluite it down with more water to your desired EC/PPM Cutting all N is dumb and will only cause you issues. plants need N in bloom its dumb bro science they don't, the N its uses its slightly less sure. but its not significant, and its 100% not none existent. The spots looks like issues with Ca to me. Biobzz needs CaMg added into the mix. it does not have adequate levels on its own. The feeding guide goes over this.

Not really an answer to ya question coz I know very little about deficiency/toxicity etc but I have had very similar marks on leaves if I have watered clumsily using Biobizz Bloom/Topmax. If you rule everything obvious out it might provide a explanation.