Leaves tips and edges curling under. What's really going on?

Discussion in 'Growing Marijuana Indoors' started by Ẅest Čoast, Mar 12, 2012.

  1. #1 Ẅest Čoast, Mar 12, 2012
    Last edited by a moderator: Mar 12, 2012
    After a few hours of searching GC and other forums on this issue, I still don't have a solid answer. I know there are a few things that can be cause leaf edges to curl down, but I've not been able to get to the bottom of this. Help me figure this out. Your input is much appreciated.

    Here are the details:

    Strain: Afghan Kush
    Soil: FFOF mixed with bat guano
    Light: 250w MH - 18/6 - 16" high
    Container: 7gal smart pot
    Watering schedule: every 4-5 days with filtered tap water.
    Temperature: It's been anywhere from 76 to as high as 84 during the day, and as low as 65 at night.
    pH: my tap water comes out at 6.9 and the runoff is at 6.5
    Nutes: none as of yet.
    Plant training: Started some LST'ing 7 days ago

    The plant is 23 days old. This problem started about 10 days ago. I first noticed the very tips of the leaves curling down. I thought I might be over watering (was watering every 3 days before the issue), so I backed off on watering, and have been watering every 4-5 days since. This didn't help any. As a matter of fact it got worse. Now the edges on the side of the leaves are curling under and some leaves look a bit shriveled. I have not added any nutrients yet. I think the bat guano is still providing some nitrogen. I did add some CalMag + my last watering, which was yesterday. Noticed more leaves curling under today. Is it possible my tap water has too much calcium? Can LST'ing cause the plant enough stress to show leaf deformities?

    Here are some pics. You can see some minor discoloration on the edges. Overall the plant looks healthy though.

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  2. Ok first off I wouldnt use tap water cause it has other trash in it unless ur using a reverse osmosis system. Read into those but if you don't have that or the cash use distilled water. Look more into using nutes and it's also good to know all the nutes in ur soil before you plant or transplant so you won't have this issue.
  3. I've been using my tap water on all my previous grows. Never had this problem. I do wonder if LA county water has too much calcium in it though.
  4. I use tap water for all my grows, never had a problem with it either I just let it sit for a day or two before using it
  5. Noticed some more leaves with edges curling under and some minor discoloration on those edges. Anyone else got any ideas?
  6. Update:
    I'm definitely seeing some improvement. Some of the leaves' edges have unfolded. I'm guessing it was the CalMag? Hope it fully recovers in the next few days.
  7. It could be moisture stress combined with heat stress. It happens when the leaves lose a lot of moisture due to heat, and the roots aren't able to keep up with moisture replenishment.
  8. looks like over watering...takes more then a few days to get right...depending on how saturated it actually was it still had to run out the over watering symptoms....hence the "it got worse" comment you made...stick with the 4-5 day waterings and give it 10-14 days to show signs of healing...some strains take longer to heal...
  9. IMG_20170427_124303496.jpg IMG_20170427_124254379_HDR.jpg IMG_20170425_193222731_HDR.jpg IMG_20170425_193051822.jpg I'm also having this problem but I use an R.O. my temp stays between 70-80 R.H. 50-60

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