help!!! leaves turning rusty

please help i spotted a few small rusty coloured spots yesterday but only on the leaves attached to my top buds, when i got home from work about an hour ago i went to check them and its gettin worse, the rest of the plants look healthy at the moment and would like to try and save them before it gets any worse, i have 5 blueberry that got turned to 12/12 35 days ago, iv'e been feeding them canna coco a+b, canna boost accelerator, and has just started canna pk13/14 about 4 days ago. ph levels are about 5.7 when i feed them and ec levels are now about 3.2 i have slowly increased this over time have i gone too high?

photo 1 & 2 - problem leaves

photo 3 & 4 - the rest of my plants they look fine apart from the top buds

any help would be great
thanks in advance guys and girls

yes. lol. i use bio canna vega and its strong as fuck

i stay at ph 6.5

what do u recomend flush???

i had a rust thing happen to me at the end of my grow turned out to be budrot! but yours doesnt look to much like mine from your pics but id just have have a good look round for mold!

no just plain water for a week and up your ph little bit then start on half strength for a week and increase bit by bit .
just rely on new growth for indication

i dont think its bud rot but dont hold me to that, im under the impression you get bud rot from high humidity in your grow room my humidity has never been higher than 30

i dont kno im only new to this but its best to be on the watch out anyway!

anyone else sufferd with this problem?,
would like to know the outcome,
how did you solve this?,
did it affect your crop?,
how long did it take to clear?

really hard to tell what's going on by the pics. i grow exclusively in coco, and have used canna. in coco, you don't need/want the high ppm's like in other mediums. i am usually in the mid 800's os so. sometimes a bit higher depending on the strain. i'm at a ph 5.8 from start to finish. i'm wondering if you remembered to reduce your base nutes, when adding your pk13/14? this is important, because the booster will have an effect on your ppm/ec level. if you didn't, i recommend a flush. 3x the container size, 2 gallon container = a 6 gallon flush. after that, feed at 1/2 to 3/4 strength. you don't want there to be no feed in the coco. that's a bad thing, as you'll be going from one problem to another.

thanks silky think thats what i needed to hear,
didnt know i had to reduce the a+b thought you added pk 13/14 on top bet i've nuked them
is ppm like the ec or is that somthing totally different? i only have a ph and a ec meter
i have 7" pots any idea how many liters they hold?
+rep to you silky your the man!!!!!!!!!!!!!!!!!!!!!

how much a+b should i feed them 1/2, 1/3, 1/4, ???????
what about boost???????????

ppm/ec are the same basically, both measure nute strength. just find a similar size container as your pots and use that as pot size. as long as it's close, it's cool. please, no rep. if i could, i'd turn it off, it's meaningless, just grow some great smoke. if this is your first time in coco, you're gonna love it. looks like soil, but hydro results.

just feed them 1/2 of whatever mix you've been using per gallon. i have some canna pk right here and it says 3 teaspoons (1 tablespoon) per 2.65 gallons. it doesn't have to be perfect, just eyeball it. better to be under than over though.

is your pk13/14 powder or liquid?
mine is a 1L bottle

daz321 said:

is your pk13/14 powder or liquid?
mine is a 1L bottle

Click to expand...

same size bottle, diff. label. i've had it for a few years, LOL. canna isn't as good as it used to be. they, like most others, have started watering their products down, so you may want to double check your dilution rates.

thanks again silky going to go flush them now, fingers crossed
hope to speak to you again soon
i'll keep posting how there doin.

you'll be fine...

If all you have is a ec meter (and as mentioned in other replies) ec/ppm relie on the same factors. You said 3.2 ecm!!!! Holy Bat Blunder!!!! Flush, flush, flush. The ease back into your nutes. With a max target of 2.4 ec or so.

1.8 to 2.0 is op