HELP! Yellowing rapidly week 7

[Skunkster]

Two GSC plants are yellowing rapidly in week 7. My other plants (cookies gelato, white widow) look great. I am not sure if this yellowing is natural for this strain or if it is another problem. I have been feeding regularly (Fox Farm trio, Cal-Mag, molasses).

Lights are the recommended distance from canopy (18-24”)

The trichomes are still clear and these plants need at least another 2-4 weeks before ready.

Should I be concerned? Any recommendations? What should I do?

Sorry for the poor picture which does not show much of the yellowing


8 ft x 7ft x 7 ft

2 x GSC, 2 x Cookies Gelato, 1 White Widow

2 x HLG 300L RSPEC (270 w each), 1 ViparSpectra V450 (200w), 2 x HPS 150W. (total 1040w, each light spaced ~6 inches apart)

10 gal smart pots

ocean forest soil

fox farm trio

cal-mag

molasses, soil microbes

[JeffInCanada]

Hi Skunkster
Those plants look pretty good at this stage of the game. You've done a great job. You're still going to get a great harvest. It's probably that strain is a little more finicky about something. Any idea of what your soil PH may be? Ever measure the PH of the runoff water?

[Skunkster]

Hi JeffinCanada, thank you for your response. I am happy knowing my plants have a chance! I have measured the ph of my water which is usually ~7-7.5 . I do not add much ph down, if any, because the runoff water is ~5.5 - 6 . I have not measured the ph of the soil. What is the best method to do so? Do you measure only the top of the soil or do you get a sample from down further?

[JeffInCanada]

Skunkster
The only method that I use to estimate soil PH is measuring the PH of the runoff water. Just like you did. Perhaps your measured runoff water PH is a clue for you. Check the GWE articles on Calcium and Magnesium paying close attention to the recommended soil PH for proper uptake. Your soil PH may be a little low. Just try and steer this grow home as best you can. In the future look into keeping the soil PH above 6.0

[Skunkster]

Thank you Jeff! Very helpful