Do u know what is causing this?

This is my 3rd crop in a row that this is happening to. The leaves start by by curling inward and down, then they change to deep purple and yellow, then brown and dies. I use General hydoponics and have been following there mixing instructions from there catalouge. I also use super thrive and monster bloom during flowering. I have had sucseful crops in the past but no luck in the last year. Any help would be awsome.

Hi Puff... It definately seems to be a P deficiency to me (phosphorus).. Are you using Soil or hydro?
And please throw the superthrive in the bin and burn it!! it's absolutely no good during flowering man.
Also, what are your temps like?

are you giving them too much nutrients? and are the roots aired out to breathe

what stage are you at in your grow?

trichomeKid said:

Hi Puff... It definately seems to be a P deficiency to me (phosphorus).. Are you using Soil or hydro?
And please throw the superthrive in the bin and burn it!! it's absolutely no good during flowering man.
Also, what are your temps like?

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I agree, superthrive is great early in veg, but use it during flowering and you are only extending the flowering time. And the P def, what is your ph? Using r/o water? If so, using calmag or equiv?

cowboylogic said:

I agree, superthrive is great early in veg, but use it during flowering and you are only extending the flowering time. And the P def, what is your ph? Using r/o water? If so, using calmag or equiv?

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I'm using soil (pro mix 4), my temps range from 15c to 20c, humidity is pretty high at 50-60%. I have used dehumidifiers to drop it th 25-30% but it didn't seem to help. they are in 3 gallon pots and i feed them once a week 500ml each. When I drop the humidity i have to feed twice a week. I have 1 cubic meter of space set up with 2 1000 watt sealed lights, but if I use anything more then a 400 watt they just droop and stunt. I am in week 5 of flowering and the plants seem pretty stressed. Also I have 5 plants out of 16 that are right curled in and down and just cant get them back. everthing I read talks about leaves curling up, but not down. Anyone know what causes this?

sounds like we have a Canadian here
No worries I am as well.
So why is superthrive shitty to use in Flower? It's not allowed to be sold in Canada, but we have a store that sells it privately. He say's its a plant steroid and how does it keep your stuff flowering?
Keep your plants under the light!! your 5 weeks in now, just make sure u water heavier when your not feeding.. See plants wil consume more water in these hotter temps. If you dry your plants out hard, give them a light water and than feed next day. dont feed when your plants are dryed out and leaves wilting.. If u do, your plants will lock, faster and easier. Mybae this is a cause for your Def.
I use general Hydro NPK, around 800ppm when in flower ( i use pro mix #4) and Vitamax-instead of superthrive. I would try Overdrive if you need to. it has good NPK and u can use it in the last weeks It def will HELP big time. But those leaves show later signs of DEF so....

Puff the Magic Dragon said:

I'm using soil (pro mix 4), my temps range from 15c to 20c, humidity is pretty high at 50-60%. I have used dehumidifiers to drop it th 25-30% but it didn't seem to help. they are in 3 gallon pots and i feed them once a week 500ml each. When I drop the humidity i have to feed twice a week. I have 1 cubic meter of space set up with 2 1000 watt sealed lights, but if I use anything more then a 400 watt they just droop and stunt. I am in week 5 of flowering and the plants seem pretty stressed. Also I have 5 plants out of 16 that are right curled in and down and just cant get them back. everthing I read talks about leaves curling up, but not down. Anyone know what causes this?

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You have 16 plants in a 1 cubic meter space?? Huh? Anyway...
50-60% humidity is actually on the money why using a dehumidifier? The 1k watters can only do your plants good, that' not causing the drooping.. ONCE again 2x 1000w lights in a 1 cubic meter space?
Seems to me you having a Phosphorus lockout either because of your low temps or Ph is way out. Find out what your soil ph is at and adjust accordingly. Get those temps to around 26c or so. Your facts don't add up though, not saying you're lying, but sounds very fishy.

JLStiffy said:

So why is superthrive shitty to use in Flower? It's not allowed to be sold in Canada, but we have a store that sells it privately. He say's its a plant steroid and how does it keep your stuff flowering?

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JL I am not gunning down superthrive, it's a great product for use during transplanting and cloning and maybe a little in veg. The hormones that are in Superthrive are there to replenish what the plant has lost during the stresses of transplanting, and that's all. Don't use it on MJ if they don't need it. Some folks say they don't see a difference during flowering, but most people, including myself have expereinced very sparse buds that prolong maturity..

trichomeKid said:

You have 16 plants in a 1 cubic meter space?? Huh? Anyway...
50-60% humidity is actually on the money why using a dehumidifier? The 1k watters can only do your plants good, that' not causing the drooping.. ONCE again 2x 1000w lights in a 1 cubic meter space?
Seems to me you having a Phosphorus lockout either because of your low temps or Ph is way out. Find out what your soil ph is at and adjust accordingly. Get those temps to around 26c or so. Your facts don't add up though, not saying you're lying, but sounds very fishy.

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First off thanks for the help so far, I thought humidity was bad for them and should be around 30%, thats why the dehumidifier. My ph has been checked and double checked 6.5. I have a 4 foot x 4 foot x 3feet high space so just over a cubic meter. 16 plants in 3 gallon pots fill the space perfect. My plants are only 2-1/2 to 3 feet tall when finished. What doesn't add up? what is fishy?

I had your exact problem with the Gen Hydro nutrients. The leaves were extremely curved downward and were looking deformed, and the uppermost leaves were curling inward on themselves. This is my first MJ grow, but I think Gen Hydro's recommendations for the feed schedule are a little concentrated (I used the recommended amounts and there's salt and nutrient build up on everything), so try "flushing" them with a salt removing chemical every two to four weeks to remove the buildup(I used Clearex from Botanicare with good results!). I also have very hard water which causes nutrient lock-up, and the plants can't get the magnesium in the soup, which causes the curling. I got some hard water FloraMicro and that seems to have done the trick. Some of my leaves were so curved they didn't straighten out at all, but new leaves have since grown in straight and sticky

Puff the Magic Dragon said:

First off thanks for the help so far, I thought humidity was bad for them and should be around 30%, thats why the dehumidifier. My ph has been checked and double checked 6.5. I have a 4 foot x 4 foot x 3feet high space so just over a cubic meter. 16 plants in 3 gallon pots fill the space perfect. My plants are only 2-1/2 to 3 feet tall when finished. What doesn't add up? what is fishy?

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Puff, apologies, I didn't mean to sound like an old fart, I just couldn't picture 16 plants in a cubed meter space...You must really struggle to keep them low in that space?? Do you use any sort of pruning methods? 50% humidity is a nice level to keep. Although towards the end flowering your dehumidifier will come in handy to drop the humidity to around 30% again and pack some resin on. See how they respond to the higher humidity, that could of been your problem from the start. What strain are they? Is it the same strain you have been growing successfully in the past? Leaf curl can be due to moisture (or lack thereof) stress. See this thread for moisture stress issues by UB: https://www.rollitup.org/marijuana-plant-problems/150004-plant-moisture-stress-symptoms-solutions.html . Last thing, don't always follow what nutrient companies say you should follow, learn to read what your plants need and you won't go wrong!

looks like a nute def. to me man not sure but probably phosphorus

Puff the Magic Dragon said:

. When I drop the humidity i have to feed twice a week.

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This caught my eye. When your feeding twice a week are you cutting the PPM per feeding in half? If not, your feeding them double whatever the GH catalouge says.
I've made that mistake befor. I was feeding well under the ceiling limit, but I was feeding 2 and 3 times a week. It took a long time but I ended up with nute burn and nute def. I had symptoms of both. Nitrogen doesnt accumulate much and the plant uses lots of it, so I had a nitro def. and my lower leaves were burning up because of toxic buildup from other nutes. Your PPM will stay the same but some nutrients are more accumulative than others and will build up over time.

I also think 20-30% humidity is way low.