Low soil ph leading to nutrient deficiency

Discussion in 'Growing Marijuana Indoors' started by evangrewinski, Jun 26, 2019.

  1. Hey guys! Ive checked my run off and it is 5.8 ph. 2 Plants show bad signs of calcium and magnesium deficiency and 1 is pale green. I understand i can manage the root zone ph with my feed water. Ive been watering with ph around 7 trying to bring the ph up in the roots but it still sits at 5.8. My question is should i feed the next time say at 7.2 or 7.5. ? The girls are 20 days into flower. [​IMG][​IMG]

    Sent from my SM-G950W using Tapatalk
  2. That is what I did or a large flush with the correct ph water till run off reads what I want. I think it is suggested to use a dry amendment to fix it though.
  3. I flushed before flower . Like 5 galons each plant at 6.5 and still the ph wont change. Last straight water feed the run off ppms were only around 300 so i dont think its salt build up but who knows.

    Sent from my SM-G950W using Tapatalk
  4. Same boat and stressing hard. I feed at 7.2 sometimes and soil still wont go above 6. No idea what to do. Im Gonna add lime tomorrow but I'm 40 days into flower kind of late. So even cal mag I add ( same def also) dont think itll suck it up because the ph too low. Sucks

    Sent from my SM-N950U using Grasscity Forum mobile app
  5. It’s not the PH, anywhere between 5-7 you’re good to go.
    Your problem in my opinion is your light is too close. You’re also slightly overwatering. But you can see the purple stems and the purple interveinal spaces I’m the leaves. This is a mag deficiency caused by too much light. You’re still ok but I would put your light at least 3-4 feet above your plantas
    • Like Like x 1
  6. Hmmmm. That makes some sense that the light is to low..... these ones are under a hlg 320 led at 18 inches and sick. The other ones i have are under 2 mars hydro pro 2 epistar 80 and are doing great. way less intensity. Thanks for the help!

    Sent from my SM-G950W using Tapatalk
  7. I agree with light being too close.

    I have HLG 320w XL RSpec 3000k and I had my plants at 20" from light and showed same symptoms. Now at 24" and they are loving it.

    I water/feed at 5.8-6.5 ph after using ph downer. Tap water is 7.8ph and my soil always reads 7ph so I try to water around 6ph

    Should add that my plants are still adjusting to this light as they have vegged under two burple LEDs the last 2.5 weeks in this tent
    Sent from my SM-G960W using Tapatalk

Share This Page