Help: Leaves Curling Up & Brown Spots

[Numb73]

Hey guys, i’m New here, i’m Growing 3 critical autos and one of them have a leaf problem that I can’t find what it is, i’m In week 3 of flower and the plant top leafs start curling up and the edges becomes brown with some brown spots, I don’t know what to do.. please help me
Temps a 24/28 celsius
Humidity: 55/60%
Nutes: biobizz
Strain: critical +2.0

 

[bluter]

looks like potassium deficiency. flowering cannabis goes through potassium more than any other stage.

 

[Numb73]

I’m confused between potassium, calcium or phosphorus def, i have already make 2 flush’s and things don’t stop going bad, what should I do?
Sorry for the English.

 

[bluter]

if you already flushed, get a pk booster. flower booster is the same thing. i'm not sure what you have available for nutes where you are. try to get one for cannabis specifically.

your english is fine.

 

[Numb73]

Thanks, I’m from Italy,
I’m using biobizz nutes so bio grown, too max and bio bloom, Did you have some names of ok boosters ? It’s my first grow.
Someone tell me that can be a heat stress what you think ?
And should I return fed them ? Only the older plant is showing this symptoms and the young one is starting to show some of this def, only the too leaves seem to be affected

 

[Metal Halide]

Since you said you flushed twice. may i ask, is it uptaking around the rootball/mass ring ontop? You said its only the top ones, If the plants uptaking water, then its thirsty. You havnt provied any info on lighting and it may be light burn/heat burn but i would also do a mite/pest check and then once you have checked all that then feed nutes at 1.6 EC & 6PH with an all rounder macro/micro nute in it, Flairform CMX, CalMag ect. dont go crazy on PK. Try to maintain a 123 NPK ratio at that stage with some silica and molasses if you can get some. Feed root ball very lightly without runnoff since you have already flushed twice and let some good stuff start to thrive again

 

[Numb73]

Thanks for reply!
For lights i’m Using a full spectrum 300w led light and from the top of the highest plants are about 40cm, but some of the lower buds are starting to have this leaf issue. What you mean for uptaking around the root ball?
There’s no pest or mites I have already checked. It look like after I flush twice things are going more bad !
I can get molasses only and some sensi cal mag, and what u mean for feed the root ball? You mean feed her with molasses and silica ?

 

[Numb73]

Since you said you flushed twice. may i ask, is it uptaking around the rootball/mass ring ontop? You said its only the top ones, If the plants uptaking water, then its thirsty. You havnt provied any info on lighting and it may be light burn/heat burn but i would also do a mite/pest check and then once you have checked all that then feed nutes at 1.6 EC & 6PH with an all rounder macro/micro nute in it, Flairform CMX, CalMag ect. dont go crazy on PK. Try to maintain a 123 NPK ratio at that stage with some silica and molasses if you can get some. Feed root ball very lightly without runnoff since you have already flushed twice and let some good stuff start to thrive again

What you think if I take AN Rhino Skin and Bud candy ?rhino for silica and bud candy for molasses, or should I take grama’s molasses and other silica ?

 

[bluter]

molasses is good. it has potassium, calcium, magnesium and other good stuff plus simple sugars. use unsulfured blackstrap molasses if you can get it.

 

[Numb73]

Is bud candy from advanced nutes good ? Did u think molasses will solve my problem ? Some days temp reach 30 Celsius cause here is summer and is too hot

 

[bluter]

Is bud candy from advanced nutes good ? Did u think molasses will solve my problem ? Some days temp reach 30 Celsius cause here is summer and is too hot

i still think your plants are looking for some potassium. they don't look late enough in flower to be eating the leaves yet, but that may have started already. the buds are drawing nutes from the leaves so they can build.

they are drawing them from the leaves as a response to not getting the needed nutes from the soil, or as a result of a ph lockout. since you flushed i assumed it's not ph. that could be wrong tho.

molasses has potassium, but maybe not enough. i know it's an old school way to get it. it's mostly used as a bud booster. that's how i use it. i've never used a commercial bud booster. i have used some enzymes.

i am not in soil any longer and my knowledge is limited.

 

[Numb73]

Yes I know, rhino skin and bud candy have fosforo and molasses, rhino skin will protect my plants from heat stress, I think my girl had more than one type of def, I just don’t know what to buy to solve this problem !

 

[Numb73]

i still think your plants are looking for some potassium. they don't look late enough in flower to be eating the leaves yet, but that may have started already. the buds are drawing nutes from the leaves so they can build.

they are drawing them from the leaves as a response to not getting the needed nutes from the soil, or as a result of a ph lockout. since you flushed i assumed it's not ph. that could be wrong tho.

molasses has potassium, but maybe not enough. i know it's an old school way to get it. it's mostly used as a bud booster. that's how i use it. i've never used a commercial bud booster. i have used some enzymes.

i am not in soil any longer and my knowledge is limited.

molasses is good. it has potassium, calcium, magnesium and other good stuff plus simple sugars. use unsulfured blackstrap molasses if you can get it.

You mean this one ?

 

[BeanTownFan420]

My guess is three possible things to many nutes to much heat or overwatering or all of the above.

 

[Metal Halide]

Bud candy is actually a realy good product, it has multiple effect and combines a terp enhancer and a raft of other things. Too expensive for me and im not a fan of advanced. Id just go with blackstrap unsulphered. The production of it contains almost every mineral on earth but more importantly since you flushed i said to use it to help feed the soil and get the beneficial bacteria going. So are they uptaking?

 

[BeanTownFan420]

Either way its an auto so there is nothing you can do now to help it but let it finish tinkering may only make it worse.

20190622_164626.jpg

• BeanTownFan420
• Jun 22, 2019

My critical purple auto.

 

[Metal Halide]

only way to tell at this stage is to see if they uptake that PH water imo. It will tell you what going on. If the new growth continues to exhibit problems then is deficient, If they get healthier then its lockout.

 

[BeanTownFan420]

Good luck.

 

[BeanTownFan420]

Hey guys, i’m New here, i’m Growing 3 critical autos and one of them have a leaf problem that I can’t find what it is, i’m In week 3 of flower and the plant top leafs start curling up and the edges becomes brown with some brown spots, I don’t know what to do.. please help me
Temps a 24/28 celsius
Humidity: 55/60%
Nutes: biobizz
Strain: critical +2.0

That plants more like 30 plus days into flower from the looks of it.

 

[BeanTownFan420]

Once an auto shows its preflowers she has already been flowering for over a week.