help with sick plant with brown spots

[bluesbreeder]

hi all,

i'm growing a Auto Ultimate that really was a normal photoperiod after 10 weeks i figured it out.
everything was going great all the weeks just had some burned tips so i corrected the feeding. my plant was groing very tall and was almost hitting the light when i saw some leaves got burned.
i raised the light so high as i could. but now a few days later the brown spots are getting bigger.
it looks like cal/mag problem? but because i feed her call/mag from AN 1ml per liter + the whole nutrient line of them so i'm having doubts it's call mag problem. ps : i only use half of what AN recommends.
the feeding water i give is 6 ph i'm growing in Coco with perlite.


here are some photo's if you guy's have any advice.

Cheers

 

[Waira]

nice spears mate! ...but a sucky to hear you got an oddball throwback, this happens on rare occasion,.... Can you get me a close-up of some leaves please? This looks like Ca and/or P defc,... symptoms can have some overlap, but up high, Ca is more suspect... for Ca-Mg, at 1ml/L it may not be enough, especially under LED,... and the low feed regime,... pic me, and we'll see, but likely giver=n her size, time to up nutes more and start with whatever passes for bloom booster in AN line,... (higher PK)

 

[bluesbreeder]

nice spears mate! ...but a sucky to hear you got an oddball throwback, this happens on rare occasion,.... Can you get me a close-up of some leaves please? This looks like Ca and/or P defc,... symptoms can have some overlap, but up high, Ca is more suspect... for Ca-Mg, at 1ml/L it may not be enough, especially under LED,... and the low feed regime,... pic me, and we'll see, but likely giver=n her size, time to up nutes more and start with whatever passes for bloom booster in AN line,... (higher PK)

well i think it's also Ca deficiency i gave her 2 ml per liter cal mag with the next feedings.
but i lowered the nutrient because of burned tips of leaves but half dose of AN is more then enough very powerful stuff .
thanks for your help !

 

[Waira]

Hmmm, I need some clearer shots closer up,... here's the challenge; one of these is Ca defc., the other is P defc.--->

---- hard to call, right? Worse, during bloom when P demand is highest, it can hit up higher than usual as well; Ca is poorly mobile within the plant, P is mobile (can be translocated from older, lower established tissues to new growth for support), so here, even where it hits isn't that good of a clue; immobile nutes hit up high, mobile tends to hit lower, but not always.... so other clues need to be found... red petioles (leaf stems) = P,.... necrosis following along the lateral ribs and midrib = Ca,... And there's very possible chance you need more of both, so muddy the diagnostic waters get!

 

[bluesbreeder]

---- hard to call, right? Worse, during bloom when P demand is highest, it can hit up higher than usual as well; Ca is poorly mobile within the plant, P is mobile (can be translocated from older, lower established tissues to new growth for support), so here, even where it hits isn't that good of a clue; immobile nutes hit up high, mobile tends to hit lower, but not always.... so other clues need to be found... red petioles (leaf stems) = P,.... necrosis following along the lateral ribs and midrib = Ca,... And there's very possible chance you need more of both, so muddy the diagnostic waters get![/QUOTE]

here is a close up off a leave . al the brown spots are on the upper leaves. the closest to the light . that's why i thought it was lightburn.

 

[Waira]

oops! forgot to mention, top pic is Ca defc, bottom is P,... Ah, that's Ca defc. in that latest pic for sure,.. finer scattered rusty spotting,... up high because it's poorly/immobile, and near the lights too could be a contributing factor,... too bad you're in bloom, otherwise the best, fastest fix would be a foliar spray,... but this far into bloom it's more risky for mold, and the plants aren't in dire straights at all! Ca defc. damage won't repair either, so what you want to look for is halting of progression,... stay on the Ca-Mg

 

[bluesbreeder]

oops! forgot to mention, top pic is Ca defc, bottom is P,... Ah, that's Ca defc. in that latest pic for sure,.. finer scattered rusty spotting,... up high because it's poorly/immobile, and near the lights too could be a contributing factor,... too bad you're in bloom, otherwise the best, fastest fix would be a foliar spray,... but this far into bloom it's more risky for mold, and the plants aren't in dire straights at all! Ca defc. damage won't repair either, so what you want to look for is halting of progression,... stay on the Ca-Mg

well i did what you said i gave her more nutes and also add 2 ml per liter Cal mag . nothing more a can do for now i think my Ca problem could be caused by my ph in my coco soil going up and down. thanks for the advice man