Leaves look dirty

[wolfalias]

Started growing 1 white widow auto, around the first week of November. Not wanting to waste the light on only 1 plant, I also started 2 others from some seeds that had been in the fridge for 15-20 years. growing in soil with 400w MH for the first 31/2 weeks, till the auto started flowering, then switched to HPS. No nutes the first week or two, then various others around weekly - 5-1-1, Cal-Mag, micro, etc.. 0-10-10, once they started flowering. 24 hours of light the first 2 weeks, then 18/6, till week 5, then 12/12. Shortly after Christmas, the leaves on the fastest growing plant(not the auto} started looking like there's dirt running down the middle of the fingers on the leaves. The thing is, it's only in the middle of the plant. the bottom part doesn't have it, and the top part doesn't have it. The plant is 4 feet tall right now. First photo, the flower in the bottom of the pic, is from the other plant. Second photo is just a shot of the entire setup(mostly).

[Mr.furley]

What's your ph?

[wolfalias]

When watering, I've kept the pH between 6.2 and usually around 6.8. I'm wondering if it was some sort of nutrient deficiency, that I ended up getting fixed. Bottom of the plant is ok, then there's a section like this, then, the top third looks good.

[Potted]

Could it b root bound? What size pot ? And how’s the drainage?

[wolfalias]

5 gallon pot, originally came with cat litter in it, I wondered about that too, because before, seemed like it was draining ok, but now, not as well. Still seems to be growing ok though. Frustrating not knowing for sure what happened.

[Potted]

Drill sum more holes in the sides low to the bottom 1/2”-3/8” that should help with daranage if that the the problem, if not u have lost nouthing

[Eliot Pryor]

Is the auto-flower 4 feet tall ? I'd pull those ugly leaves off and forget them . Nice gow !!

[wolfalias]

No, the Auto is maybe 2 feet tall. Been having to put stuff under it, to keep it closer to the lights. probably harvest in about 2 weeks. The auto that is. The other 2 need at least another month.

[Mr.furley]

wolfalias
from the look of your leaves and the purple stems it does look like a potassium deficiency but I'm not convinced. The reason I say this is the heavy amount that you are indicating you're giving above, in that incense I would lead to believe your pH is off or as Potted has ask a small pot or a root problem.
I would like to ask if you have light in the middle of the plant or just the top and bottom? What kind of light?
Have you flushed your plant?

[wolfalias]

Only gave this plant 0-10-10 once on 12/22, because I thought it looked like a potassium deficiency, from what I had read. Also read that over watering can lead to nutrient lock-out, so I let it dry out a little longer than usual. 5 gallon pot Zen Blend soil with extra perlite added. 400w HPS lite above, with CFL bulbs for auxiliary lighting for the middle and lower areas. Been using a pH meter, but I'm not real happy with the prestige meter I got. Seems to need to be calibrated almost every time I use it. I have flushed it one time, before it looked like this. It seems to have outgrown it, whatever it was, but I'd still like to know what caused it. For future reference.

[wolfalias]

Checked the pH of the runoff, the one time I flushed it, and it was 6.2

[Mr.furley]

It is possible that you have got it licked by flushing your plant and your runoff number is perfect. The shot of 0-10-10 should fix it if it is a potassium deficiency, this is common to the middle of the plant. Just keep doing what you are doing and watch that it does spead. It is worthy noting that yellow with spots can be calcium.
Make sure your pots are light when you lift them and dry to your second knuckle before watering and to always water to runoff.
Also keep your pH pen in calibration solution when off, turn on, check then place in clean water for a minute before use.
Good luck

[wolfalias]

Thanks to everyone for your help. I've come to the conclusion that it was a potassium deficiency, for whatever reason. Seems to be doing good now, so fingers crossed.