Is this a Magnesium Deficiency?!?

Discussion in 'Growing Marijuana Indoors' started by Ben Merkin, Jan 4, 2013.

  1. I have an Afghan Kush Ryder almost 28 days into flower Its FFOF soil with the FF trio for nutes. The leaves have turned yellow near the tips, rust spot with the blades curling up on the edges. I have always gave it spring water but Sunday I gave it regular tap water then the problem got bad. I checked the ph of the water and it was over 8. The temps have not gone above 82 however it is in a tent and I did not get a good exhaust fan until yesterday. What elese..last night I gave it its tiger bloom and big bloom with a tsp of molasses with water ph'd to 6.5. I looked at the deficiency charts and it looks to be late stages of a Potassium deficiency but then it also looks like a Calcium and Magnesium Deficiency. I need some expert help diagnosing and then fixing the problem as soon as possible. I have some superthrive arriving today even though I fed yesterday (I water every 4th day) should I maybe flush her with 3 or 4 gallons with a little superthrive in the last gallon. Ive never had this problem before. Heres some pics I took this morning. Thank you.

    ps. I posted this in the sick plants forums but it had 70 views and no comments so i posted it here

  2. #2 Scarem, Jan 4, 2013
    Last edited by a moderator: Jan 4, 2013
    Definitely looks like Potassium Def... perhaps N too. At PH of 8 you'll be getting lockout and salts, I'd flush it through with 6-6.5ph water and see if that helps (keep the nutes in there as you normally would as you'll be flushing out their salts within the soil).

    I brought my water down from 7.8 to 6.3 with about 0.5ml of lemon juice per l.. Some people may find PH down better but it's all I had at the time.

    Any leaves that have suffered a severe deficiency may be best being taken off as they won't recover - though best have this confirmed from a guru from the community first.
  3. #3 Spaced, Jan 4, 2013
    Last edited by a moderator: Jan 4, 2013
    Its definitely a lockout due to a PH imbalance. Drop your soil ph down to 6.5-6.8, dont feed them nutes again until your PH is right..otherwise it will build up.

    And yes, as the above poster stated, just remove the affected leaves as the cant recover, just focus on healthy new growth.

    Funny thing, i have a Afghan Kush x Skunk on week 4 of flower too with the same exact issue. Due to my ph meter breaking and the mail being slow haha
  4. Thanks guys im gonna flush with 3 or 4 gallons of balanced water. When i take of the dead leaves do i take off just the leaf or the leaf and stem?
  5. Just pinch the stem of the leaf. It doesnt really matter where.

    Good luck!
  6. Thanks Spaced and Scarem. Ive been stressing all day and night. I feel a little better now
  7. No worries mate, glad I could help.

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