could this be a deficiency from lack of nutes?

[sourdieselyumyum]

medium is coco coir strain is barneys farm critical kush nutrients are advanced nutrients ph perfect connosuier big bud bud candy b52 voodoo juice I had a little salt build up 4 or 5 days ago ppms around 1200 or so when id water with 700-800 ppm I got rid of the excess ppm and have had watered with 650 ppm and that what the runoff was im just wondering if there showing these signs cause I need to up the dose of nutes heres what I put per gal of solution 10ml a+b 5ml big bud 5ml bud candy 5ml b52 8ml voodoo juice I am day 24 into flower any help will be appreciated

 

[AimAim]

It could be, of course. If it's just the one leaf you pictured I would not get too concerned. I always lose a FEW larger older fan leaves once flowering commences, while rest of plant looks great.

 

[SnapsProvolone]

Low on phosphorous

 

[vostok]

Early to mild nute burn,....give the plant a through watering and avoid feeding for 2-3 weeks

 

[AimAim]

Early to mild nute burn,....give the plant a through watering and avoid feeding for 2-3 weeks

What nutrient has it been burned with exactly?

(hint.... that's not what nutrient burn looks like, but keep typing)

 

[sourdieselyumyum]

I figured phosphorus maybe calmag because I haven't been adding it to my RO water but advanced nutrients connosuier has it in it from what im told by there reps so I don't add it but it think It probably lack cause there 3 1/2 weeks into flower so they should probably be getting around 800-1000 ppm but I had to flush them a couple time cause there was a build up of around 1200-1500 and ive noticed little burn before this what do you guys think I should be feeding them ppm wise if I follow advanced nutrients recommendations with full dose of base fert then I add 1/2 dose of additives ppm I get is around 1000-1100