Please help I think cal/mag but idk

So I’ve been battling this problem for about 2 weeks now and it just seems to be getting worse the brown spots started on the middle fan leaves towards the tips leaves where yellow where the spots where, tips of leaves are clawing downwards. I gave some Epsom salts yellowing seemed to go away but spots are getting worse. I top dressed with gypsum but it wasn’t flour they where bigger pellets so probably take to long to break down. I’ve been feeding cal/mag in my water the whole time though so I’m just confused I’m 5 weeks in flower. I did go a little crazy about week 3 I was using too much molasses I stopped that entirely and I was using budswel every other watering I stopped that aswell. I top dressed a few days before the problem really started with earthworm castings, azomite, sea bird guano, and 4-8-4 bloom all from down to earth. So idk if it was too many nutes or if I’m being lockout out or what. I’m in a 10 gallon pot, coco/earthwormcastings/pearlite mix water phed to 6 every time but the last few days I raised it to 6.2-6.5 thinking that would help with calcium uptake. I do have a bunch of springtails in my living soil but doesn’t seem to be over infested. And they are beneficial to breaking down my amendments. Problem just doesn’t seem to be getting better don’t know what to do. I don’t want to make it more complicated than it already is so I’ve basically been using just phed water the past 3 waterings. Any help would be great so I can save my first plant.

Buds are developing fine plant looks ok. Stop adding stuff to it, all your doing is adding more possible reasons for problems. Once a leaf or part of a leaf goes yellow or developeds a brown spot or spots those yellows & browns will never be green again, its the type if dirty you cant wash off if you get my drift. Your plants look ok just give them what they need. They are way too far along in the cycle to correct any problems. Stick to the fundamentals

What kind of soil are you using as the base for the soil?

Dont even worry the more I look at your plant the more impressive it becomes. Thats guna be some nice buds! Just pick those big old scabby leaves off.