CalMag & FinalPart in flower final 2 wks

If you follow TAs directions, you just add it to your pH adjusted water and use it alone. I personally haven't used it(or other "finishing" products either) though I DO use PK boosters early on in flower. Really I wouldn't stress chasing any deficiency issues that late into flower. You can't fix a deficiency issue overnight and you won't see signs of improvement for a couple weeks. By the time it's corrected you'll be chopping the plant and it won't matter anymore. Just get it across the finish line and take the knowledge into your next grow.

Plant need calcium at all times, so it should never be withheld. (and magnesium and all the other nutes, too). that being said, looks like you need to tone down the nitrogen a bit, or scale it back sooner if you already did. Glossy leaves are a sign of too much N. 'cal-mag' products often have N in them, so consider that in the adjustment too. deficiencies do not block or lock things out. Too much of something 'can' lock stuff out - or if pH is way off. "Mulder's Chart" is a visual that shows the various relationships between nutrient molecules -- which are antagonistic and which are stimulative relationships. Sometimes adding more of something requires an uptick on other things to keep up.

A def don’t block the nutes but if you have to high EC in ur medium you will get blocked and that’s what it looks like. Your leaves are super darkish it means that you have to much oh nitrogen in them and when it just keep fills up with nitrogen after a while you’ll get blocked. So try to keep down the nitrogen intake because you already have a loooot! And try to lower the EC in medium. Feed until u get the same EC as you pour in to the medium. You are getting close to harvest so no need to a flush with only water it will only harm the final results so wait until the end flush with that. But as I said you can flush it with nutes until you get the right EC in your run off and she will recover and probably stop developing rusty spots. And keep the ph right ofc but that’s something you already know probably. Good luck my friend 😁🤩💪🏽 may the buds be with you