Need some advice

What up everyone ?
Hope all is well
Was trimming few of my ladies, I notices some leaves browning and yellowing. First time seeing this, usually some cal mag fixs any minnor yellowing.

Some info about setup
2 week flower strain PK
1000w
Advance nut 3 Part
Big bud
Cal mag
Superthrive
Ppm 1000-1200 ph 5.8-6.3
Med is 80 20mix coocoo &hydro pellets
Ebb 5 gallon buckets

Thanks for stopping by

are you sure the big bud is necessary? I suspect you're over doing it on the ferts. I thought such high ppm is used in hydro like dwc, not so much for coco.

looks like a lot of brown spotting and yellowing, also some burning. which 3 part system are you using from advanced nutrients? looks like your ladies are just starting to flower? I wouldn't let the ph go past 5.9 during flowering and stay below 900 ppm. also are you using superthrive every feeding? superthrive is extremely concentrated, I wouldn't use it unless you have a really bad root problem, even then only once at this stage in their life. how is your temp and humidity? 78 degrees with 30% humidity works well indoor when flowering. I would flush those ladies with clean fresh water then start with a simple 3-20-20 nutrient at half strength.

Nute burn from over fertilising causing lockout I suspect as I can see some salt build up on your last pic ?

I will try fushing thanks everyone