Phosphorus? Potassium? CalMag? What is going on here?

Some are just yellow spots and of no concern - you will never have 100% perfect leaves 100% of the time. However, other leaves are certainly indicating problems somewhere. I would say, after looking at your diary, the damage is being caused by burning and not any deficiencies of any sort. My guess would be that you are giving bloom booster as well as a P/K booster together and it is more likely your plants are suffering with either phosphorous or potassium over load. My advice would be to just give plain water for the next 3 irrigations to let the substrate leach for a bit to remove any P or K build up, then when you go back to feeding, use only the Ata PK 13/14 or the B'Cuzz universal coco booster separately, and not together in the same feeding. It's one or the other, not both. Your plants will be fine for 3 irrigations of plain water, in fact it is probably wise to use just plain water every third or fourth irrigation to prevent any build up of mineral salts, and your plants will have a chance to scavenge any left over nutrients in the coco before being topped up again. Growth won't be affected, but your coco will stay "cleaner". Hope this helps..... Organoman.