leafs curling downward on some plants

hey guys
im pretty new to this and if someone with experience could give me advice i would appreciated it greatly
I have 9 plants 4 grape kush 4 of a blueberry strain and 1 lemon hase and they all were doing great i kept them in the 18-6 cycle for 5 weeks till they were all between 18 and 24 inches tall then i flipped to 12-12 im starting to see alot of pistol production at bud sites but 2 of the grape kush plants and my lemon haze have leafs that are curling downward. i was worried that it was due to over watering from what i have read on the forums but i only water every 3-4 days just when the soil dry then i water till i have runoff in the botom of the pots. i water all the plants the same and only 3 are showing the curling leaves could it be something other than over watering?
any advice will be greatly appreciated like i said im new this is my 1st indoor grow
my room has to 600 w hps lights and my temps are steady at 67-70 during dark period 74-80 lights on so i dont think its a temp issue but like i said i dont know im new to indoor growing.
thanks guys

pictures would help alot. sounds like overwatering if its just curling downward? How loing have they been showing signs since you last watered? they may be stress from the light cycle change as well
whats the ph?
whats in your soil?
what are you feeding them?
and grape kush sounds damn good

ya we need pics and more info.
To be able to help you

Without pics I would suggest paying attention "like above said" to the heat and water amount.

Pictures would help but are the leaves standing up, as in not limp and hanging, but look like if you held your hand out and curled your fingers downward? Are the leaf edges rolling/curling under giving them a thin narrow look, a look somewhat like the Cryptkeeper's fingers? Are the leaves a dark but flattish looking green and possibly a slight bluish tint to the green and have a dryish look to them but your plants are not taking in as much water as in the past?

Brick Top said:

Pictures would help but are the leaves standing up, as in not limp and hanging, but look like if you held your hand out and curled your fingers downward? Are the leaf edges rolling/curling under giving them a thin narrow look, a look somewhat like the Cryptkeeper's fingers? Are the leaves a dark but flattish looking green and possibly a slight bluish tint to the green and have a dryish look to them but your plants are not taking in as much water as in the past?

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I noticed on one of my Bubba Kush when the lights first come on the leaves has a blueish tint. Otherwise the plants are wonderful. might be just my eyes adjust to the HPS, what would cause a slight bluish tint. My wife calls it purple. (NO temps are fine.)

TheTokingKing said:

I noticed on one of my Bubba Kush when the lights first come on the leaves has a blueish tint. Otherwise the plants are wonderful. might be just my eyes adjust to the HPS, what would cause a slight bluish tint. My wife calls it purple. (NO temps are fine.)

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I have never grown Grape Kush so I do not know if in that case the color is genetic, but if not due to genetics and if the leaves are not curling down, and do not begin to curl down, it would most likely be a phosphorous deficiency. That will cause a purplish/bluish discoloration and now and then a reddish discoloration.

If they, or any others, are curling down, rolling under/taking on a narrow thin leaf blade look, and have a flat color that can be slightly bluish and look slightly dry, but not limp like over dry, then it would likely be 'the claw' which is the result of nitrogen toxicity that damages/destroys a plant's vascular system which inhibits the uptake of moisture and nutrients.

Pictures would be needed to say for sure if that is going on or not.

As of now the plant looks great. I think I need to keep a close eye on it, glad you made me think of that. We tend to subconciously dismiss problems....being stoned, denial or whatever it is. Thats why I love reading posts and offering opinions. I like to be respectfully challenged because thats how we learn.

Yes leaves are standing up it's just the tips last 3/4 of a inch that's curled downward leaf edges appear normal not curling in
Plants Seam to be taking in more water than before leaves do not have a blueish tint at all and I will try to get some pics posted I understand it's not easy diagnosing the problem without actually seeing it I will try to get some good photos tomorrow when lights come back on

dilyn1 said:

Yes leaves are standing up it's just the tips last 3/4 of a inch that's curled downward leaf edges appear normal not curling in
Plants Seam to be taking in more water than before leaves do not have a blueish tint at all and I will try to get some pics posted I understand it's not easy diagnosing the problem without actually seeing it I will try to get some good photos tomorrow when lights come back on

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Be sure to get as clear of closeup pictures as you can of the affected leaves but also clear pictures of the entire plants. Also, at what level of the plant(s) did the problem begin? The lower leaves, the middle leaves, the upper leaves and after that did it spread and if so in what direction, up or down, and if both, which way first?

my guess and from personnal experience it really sounds like you have the "eagle claw". eagle claw is mainly due to having a nitrogen toxicty which results in a complete lock out after a while thus creating those claw look leaves. you might be in the beginning stages of the claw. But thats just my guess since theres really no info or pics for that matter. are you growing in soil. what type of soil. whats the ph, what type of nutes are u using. give more info and im pretty sure well will point you to the right direction bro.............

bestbuds09 said:

my guess and from personnal experience it really sounds like you have the "eagle claw". eagle claw is mainly due to having a nitrogen toxicty which results in a complete lock out after a while thus creating those claw look leaves. you might be in the beginning stages of the claw. But thats just my guess since theres really no info or pics for that matter. are you growing in soil. what type of soil. whats the ph, what type of nutes are u using. give more info and im pretty sure well will point you to the right direction bro.............

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That was mentioned .. other of course than it is not due to a case of lockout, as in pH being off, but instead because it causes a vascular breakdown within plants that inhibits the uptake of moisture and nutrients and correcting a pH problem will not solve/cure vascular damage.

If they, or any others, are curling down, rolling under/taking on a narrow thin leaf blade look, and have a flat color that can be slightly bluish and look slightly dry, but not limp like over dry, then it would likely be 'the claw' which is the result of nitrogen toxicity that damages/destroys a plant's vascular system which inhibits the uptake of moisture and nutrients.

Click to expand...