Yellowing on lower leaves

[StonerThor]

Howsit!

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

 

[StonerThor]

Or maybe Manganese deficiency? Only noticed little brown spots in the yellow area recently..

 

[NuttyProfessor]

this will help you get the right answers my friend

How to Ask for Grow Support

 

[NuttyProfessor]

you would really need to find ph , too high will lock out and too low will lock out its a fine line , you need roughly between 6 to 7 (6.5 best) not 100 percent but my guess is magnesium deficiency, i think theres a lock out some how ..

like ive said not 100 percent , i am sure others will chime in though

this will help you understand how important ph can be
PH and Nutrient Uptake charts!

 

[StonerThor]

Just remembered that the plant showing the yellowing was the odd pot out and had less worm castings/ more potting soil in it compared to the others, thanks for the input will have to look into my ph.

 

[StonerThor]

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

 

[devilish]

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.

 

[NuttyProfessor]

are you sure you have that right way up , i thought lemon and vinegar put it down and baking soda put it up ? i must double check this

 

[NuttyProfessor]

yes ive just tested that and vinegar does bring it down and fast

 

[devilish]

lol yeah lol...I corrected it...My mind has a hard tie staying in one place and bounces all over when I am unmedicated....And I am at work so Unmedicated Day!

 

[NuttyProfessor]

easy done mate

 

[devilish]

Thanks for pointing that out though. I appreciate it!

 

[StonerThor]

Thanks for the feedback. Much appreciated

 

[40 years since first grow]