2 YEAR consistent Deficiency issue - Purple fan leaves

Hi All,

For the past 2 years, I have grown almost exclusively in coco using GH 3 part. Prior to that I have grown DWC and soil and have never seen this issue. In the last 2 years I have grown 15-20 plants through flower and everyone has seen this issue at some stage. I have had people on various forums (including this one) tell me that it wasnt an issue or point to things like temperature or humidity. Given that I have tried multiple strains, temps, humidities I can only come to one conclusion, a DEFICIENCY or excess of something.

To prove this I grew a DWC plant and a COCO cloned from the same plant, in the same tent, with the same nutrients. The DWC showed no signs of purple fan leaves and the coco turned purple.

I became fed up with not knowing when my most recent grow started to show signs of purpling. Below are some pics, would really appreciate some help. Thanks.

Are you using cal-mag with general grow , micro, bloom ? If you are that’s the problem the calmag you only need every other week in veg and maybe once a week on flower bloom but not every watering , what is your ppm on your water you using to feed your plants with and the ph , if it’s tap water from the faucet spicket, that can also be the problem , and that’s a animal of a it’s own , Let me ask this ? Do you have a fish aquarium in the home over say 20 gallons maybe , are you can catch rain water as much as 50 gallons per full grow and that should help the high calcium trace minerals either in the dirt or the water are you adding to much cal-mag from seedlings :seedling:, Epsom Salt is a better alternate than chelated calmag , if you choose to used it , try getting a much lower number than 3% can cause high nitrogen release at a lower ph reading early in veg if you run your soil ph 5.5 - 5.8 can be also the culprit , so again many variables to say which , only you know what your doing actually each time , but those are a few ways that can cause it without affecting much of the plants growth to transition to flower phase without being noticed !

COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non applicable)

-What strain, Seed bank, or bag seed (photo or auto)
-Age of plant
-Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
-Vessels: Type and capacity of container (fabric, plastic, etc)
-PH and TDS of Water, Solution, runoff (if Applicable)
-PPM/TDS or EC of nutrient solution if applicable
-Method used to measure PH and TDS
-Indoor or Outdoor if indoor, size of grow space
-Light system List brand and wattage/spectrum
-Actual wattage draw of lights
-Current Light Schedule
-Temps; Day, Night
-Humidity; Day, Night
-Ventilation system; Yes, No, Size
-AC, Humidifier, De-humidifier,
-Co2; Yes, No

If growing Hydro some additional questions:

-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
-Temperature of reservoir
-TDS of nutrient solution
-Amount of air to solution

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

Why Some Marijuana Plant Stems are Purple (Cannabis Purple Stems) (ilovegrowingmarijuana.com)
Maybe this will help…