Auto Nute Burn?

Discussion in 'Growing Marijuana Indoors' started by jimsonweed, Mar 6, 2024.

  1. Hi all,

    Growing Mephisto Double Grape auto in FFOF soil. Using General Hydroponics Trio nutes at 1/4 strength (+CalMag); comes out to about 450 ppm or so. Using LED lights. My plant has been extra thirsty lately, so have been watering every 2.5 days or so (I only water when pot is light and soil is dry). I think this is nute burn? Leaves are dark green, many of the leaf tips seem to have that characteristic burn. My runoff pH is right at 6.0 and PPM 500-600. She's otherwise a vigorous grower, I'm at about 7 weeks from seed.

    I've been doing water -> feed -> water, but I'm wondering if I'm starting to burn her since I end up feeding twice per week at this watering rate. I was going to start doing 2 waters for every feed (target one feed per week) to help combat this. Any thoughts? I appreciate it!
     

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  2. She looks very healthy to me ;)
     
  3. I've killed plants before with nute burn, so I am very sensitive haha. I just did another plain watering and the ppms were 650s; I think I'll probably just supplement with CalMag and give plain pH'd water until the nute burn stops or the ppms drop off too much before feeding again.
     
  4. I hear you. You know, some autos, during transition, they actually use a bit less nitrogen (ime). Here's a little writeup I keep handy for us auto growers
    Bato of the Systems
     
  5. Very helpful, thank you! This is my first auto, it's amazing how quick they grow and how little nutes they need!
     
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  6. yes, ik, but sometimes they do need a lot of nutes, like later on some get very big, especially Mephistos ;)
     
  7. Great lol. Well I think I will let her guide me when she needs more. The nute burn seems to have stopped progressing since I first posted. I'll be doing my third plain water in a row today or tomorrow, then I'll have to decide when to feed again. Maybe a light feeding after that and then back it off to once per week or once every 2 weeks unless the runoff PPMs drop or she starts getting pale.
     

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  8. Yes she is looking good and I wouldn't worry about the little tip burn.
    The last mephisto double grape I grew I got over a pound from her, she is on my journal. Good luck
     
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  9. you did get a nice crop with that monster ! More than that, I bet that smoke is super potent; I know the CCxFS I have, no way I'm smoking a batty to myself.
     
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  10. Whoah! I actually stumbled across this when I was first looking at double grape...that's amazing! Yeah I think I've got her dialed in at this point (hopefully). Definitely a different experience than the photo grow, that's for sure
     
  11. Do you all think I should add some nutes? She is looking good, I haven't added any since I originally made this post. Runoff PPM is still 700. I think she only has a couple of weeks left (we're at 50 days, cycle time is supposed to be 65-70 days). It feels weird not to feed her, but she's doing so well! I definitely don't want to burn her. I was thinking of doing one more feeding at some point, but I was going to wait until she started showing that she needs them.
     

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  12. That plant has about 6 weeks left to go, once your plant starts to flower then you can start to count the days she has been flowering.
    She will go 8 weeks so I'm sure you are going to have to feed.
     
  13. Oh interesting, the mephisto site tries to say it takes 65-70 days from seed! That's good to know. I'll def start feeding again soon, probably next watering.
     
  14. Yes I feed my autos every time I water/feed at 500 ppm but with my new master blend bloom I went up to 600 ppm in flower, right now the one's I got growing in 3 gallon air pots are getting feed every day until run off in my promix and perlite. The pots are lite every morning.
     
  15. Hi all,

    As expected, you all were right! I think I'm now starting to see some signs of underfeeding. Probably pretty early though. I've now done two consecutive feedings, one at 1/8 strength and the next at 1/4 strength. PH is good at about 6.0 in runoff (going in around 6.8 or so). Runoff PPM yesterday after second feeding was about 680 (530 on prior feeding).

    My plan was to do a plain watering next and then reassess additional feeding. Thoughts? I'd hate to over or under feed at this point in the grow. Thank you all.
     

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