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Yellowing on lower leaves


Well-Known Member


Its my first grow and i'm 3 weeks into it, one of my plants is starting to show signs of yellowing on some of the lower leaves, my first thought was a nitrogen deficiency or maybe Manganese deficiency based on what I'd read about the topic however I'm not certain. Any suggestions would be appreciated.

This is a breakdown of the setup:
Strain - Unknown (Random seeds from a banky)
# of Plants - 3
Grow Type - Soil
Grow Stage - Vegetative
Lights - 250W Metal Halide
Nutrients - SeaGro Organic Plant Food
Medium - Roughly 35% Worm castings 35% Potting soil 25% Perlite
PH - Unknown
Room Temperature - 68 to 78
Room Square Footage - 2'x 2'x 4' = 16
Pests - None Known


Grow Journal of the Month: Mar 2021


New Member
Ok so I did a few tests using the strips (on a tight budget) and the plant with the yellow leaves showed a ph of below 6 (my tester shows nothing lower than 6) while the other 2 plants have a ph of 6.2

Well therein lies the problem then. Glad to see you were able to get it figured out. If you are on a tight budget you can;

Lower Ph: Add 1ml per gallon of Lemon Juice or 1/4 Tsp White Vinegar, test Ph. Add more if needed until desired 6.0 - 7 Ph is reached within the Nutrient Solution.

Raise Ph: Add a Pinch of Baking Soda per gallon of water, Test Ph. Add more if Needed until Desired 6.0 - 7 Ph is reached within the Nutrient Solution.

Or if you have the extra funds pick up a bottle of Ph Up and Ph down. This stuff is very concentrated. So use Sparingly and constantly re check Ph of water/Nute solution to make sure you don't over do it. Also make sure to stir/shake vigorously before testing to make sure it is properly mixed.

Hydrated Lime is also great for Raising Ph and is readily available to change the Ph of soil and is also water soluble so watering it in is a snap. Do not Exceed .5 cup per Cubic Foot of soil as too much Hydrated Lime releases so fast that it can actually Toxify the Soil and kill plants.
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