Day 37. Yellow/curled leaf tips. Please Diagnose.

Discussion in 'Sick Plants and Problems' started by TobintheGnome, May 12, 2010.

  1. 2 Northern Lights. 600w HPS. 2/3 FFOF, 1/3 MG Perlite. 5 Gallon Buckets. 2 fans, temps: 65-82. Day 7 of flower. 18" tall. Watered every 5 days approximately 1 gal per plant. First nutes 2 days ago. FFF Big Bloom & Tiger Bloom at 1/4 strength. I've been using vinegar & pH Up to keep my water's pH in the mid 6's.

    I've had a problem with yellowing/curling leaf tips for a few weeks now. Started pre-flowering, seems to have gotten worse lately.

    If I had to guess on what's wrong: 1) pH 2) lack of nutes.

    Please advise.


    pics to follow
  2. #3 TobintheGnome, May 12, 2010
    Last edited by a moderator: May 12, 2010




  3. Hi there, looks like a combo of a few things, have you flushed at all? Could be some buildup in the soil.

    My 2nd guess is ph swings. Vinegar is terribly unstable and won't hold the ph down. ph down is well worth the expense, or jsut add some more nutes to lower the ph if you are only going 1/4 strength. TB is pretty strong stuff, I try not to use more than 1.5 tsp ever.

    Good luck!
  4. I'm guessing a good flush with properly pH Down'd water could do some good. Tap water here runs oin the 6.9-7 range.

    IIRC, when flushing you water with 3-5x the amount of the container? Since I'm using 5 gallon buckets, I'd want to water with 15-25 gallons per plant.

    That's a lot of water.
  5. Yeah rule of thumb is 2-3 times pot size, so 10-15 gallons. It's a pain in the ass and if your soil drains poorly it can take hours :mad:

    You can take readings from the runoff and see the flush in action. If you pour in some RO or distilled water and get the ph of the runoff, that'll really tell you if you have build up. 6.4 or lower usually means there's lots of nutes (salts) which lowers the ph of course, so flushing that out will have the runoff read a little higher. You want it in the 6.5-7.0 range.

    If you have a TDS meter it's a lot easier. Measure the runoff, if it's 600ppm or more then I'd flush it until it's below 300ppm, the lower the better.

    Just measure every gallon or so and you can see the progress and determine when you are done.

    Hope this helps!
  6. Bumping. Can anyone else offer their $.02?
  7. I have an acer plant in the garden if it gets to windy it stresses the tips of the leaves a bit like yours....? Apart from that I am no good coz i think i have just killed my first batch off with over nuting them:eek:

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