Need Help! Plants are going yellow

Hey! In need of some help. My plants started going yellow a few days ago and look very limp. I thought this was a sign to add nutes. 3 days ago this started and I’ve been adding nutes since yesterday. What do you think it is? Magnesium deficiency or under watering?

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I’d like to see a side shot to be sure, but it looks like they still have their cotyledons, and shouldn’t need fed yet. The soil looks pretty wet. Make sure you’re letting it dry up some between watering. At this age, they only need a small amount of water, and you should water around the plant, not right on it. You want those roots to seek out the water, rather than sit in it. :v:


How about filling this out so we all know what you are doing? Please be as detailed as possible.

COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can.
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NA (non applicable)

  • What strain, Seed bank, or bag seed
  • Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
  • Vessels: Pots, Grow beds, Buckets, Troths
  • PH of Water, Solution, runoff (if Applicable)
  • PPM/TDS or EC of nutrient solution if applicable
  • Indoor or Outdoor
  • Light system
  • Temps; Day, Night
  • Humidity; Day, Night
  • Ventilation system; Yes, No, Size
  • AC, Humidifier, De-humidifier,
  • Co2; Yes, No

Always try to upload a clear picture of any issues you may have to allow the community to assist you.

Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us help you in a more efficient manner :slight_smile:



Do you have a ph meter check out the runoff of your pot

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  • What strain, Seed bank, or bag seed - Grand Daddy Purple & Purple Lush from Quebec Seed Bank
  • Method: Pro-Mix soilless growing medium
  • Vessels: smart pots
  • PH of Water, Solution, runoff (if Applicable) - 6.4ph no run off yet they are still young.
  • PPM/TDS or EC of nutrient solution if applicable
  • Indoor or Outdoor- NA
  • Light system - Quantum Board 240w
  • Temps; Day, Night 21C
  • Humidity; Day, Night 54%
  • Ventilation system; Yes, No, Size yes, 195CFM in a 2x3x5foot tent.
  • AC, Humidifier, De-humidifier, - No
  • Co2; Yes, No - No

Could be yellowing from over watering or coming in contact with the soil.

Let them dry out a bit before watering. It’s a flood/drought water schedule.

Also, don’t trust pH readings from cheap “probe” style meters.

21c is a liiiittle cool. It’s workable, but 23-25c would be better.

Rh54% is also a bit low for initial veg. 60%-65% would be better.

What spectrum is your qb?

How are you testing pH?

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Assuming your meter is on, I would likely start a very low dose of your nutrients. Something like 200 ppm. Likely some damping off as the seedling has a tough time of using any trapped moisture. You might want to dome the plants and not water for a day or two while watching the plant. Lights should be at least 24" away and more likely 30" or so would be good.

I don’t think you have any real issues to deal with. Temp is a little low but it sounds like you are doing your homework and purchased quality components. By 3 weeks or so I would like to be around 400 to 500 ppm. I PH a bit lower at 6.0 to 6.2 but that’s what works for me.


Think I recommended this the other day. Will help her ‘eat’ better

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I have some Ph 6.0 water ready to go for next feeding. I increased the temp to 23/24C and they already seem happier!

Found the sweet spot. 6.2 the girls really enjoy. Mixed with some CaliMagic they grew like crazy just over night. Also have my temps at 57%RH and 23.7C. I would be totally lost with the advice i am getting from everyone! Thanks again!

Now I’m off to Toronto for a few days. The wife gets to feed the girls :grin:. Once I am back I will start adding the full flora series for nutes.


Sounds like a win my friend! Thats one of the toughest parts to growing. Fine tuning YOUR setup to run like a smoothly oiled machine. :+1:t5::+1:t5: And even sweeter wifey will help on the trip. Now if u can get her to send pics ur really in there… (of the plants of course :laughing::laughing:)