Need HelpPlease!! Yellow leaves with very purple stems

[flyinhawaiian]

Hello all,
I'm having a issue with my current grow and looking for some advice.I have 3 Sour Diesel and 3 Mazar, 33 days old (they are pretty big for their age)

. First nutes given 3 days ago at half strenghth (House and Garden Soil A&B regiment) Distilled water and cal mag given since week one. Heres the set up. Happyfrog soil with a little bat guano mixed in, 3 gallon smart pots , just switched to 600w HPS bulb a week ago, 18/6 light sechdule . Heres the problem, large fan leaves are turning yellow with a hint of brown and all have very purple stems. seems to stay bottom to middle leaves. some plants worse than others. At first I thought they were just hungry ( I like to wait till day 30 or so to give first nutes) but the problem seems to be getting worse. On a side note I did just calibrate my PH pen and found it was off by quite a bit. Anyway check out the pic below and any help would be awesome!

 

[Heavily Medicated]

She is most definatly hungry. I just don't know if it is from lack of nutes in the soil, or the lack of availability of the nutes in the soil. You mentioned your pH pen was off. pH moves exponentially, meaning every move in your pH reading is actually 10X more or less H ions. That being said, my bet is your medium pH is starting to lock out nutes. 30 days seems to be quite a long time before starting nutes. Was she yellowing then when you added your first nutes? You need to determine the pH of your medium. If you add more nutes to a locked out soil, things just get worse fast. Taking into the calibration error of your pH pen, at what pH were you actually adjusting to?

 

[Renaissance Redneck]

HM beat me to it!

 

[flyinhawaiian]

Yes they were yellowing a little bit just before nutes. My PH pen was reading 1.5 Higher then it was supposed to read. So instead of 6.4 it was 7.4

 

[Renaissance Redneck]

Yes they were yellowing a little bit just before nutes. My PH pen was reading 1.5 Higher then it was supposed to read. So instead of 6.4 it was 7.4

7.4 is way high. P, K, manganese, boron, all are locked out, and that effects the uptake of a lot more. Do you have an accurate 8 meter to test your soil ph?
Personally, I'd water normally, pH'd to 6.0, give it a day to check for stress, then follow up with a normal feeding at proper pH, in the 6. 4 range.

 

[Waira]

guys,..

..symptoms look mostly like N defc. to me, likely from the lack-of during veg', very little stored,... but the weak bud set say P-K are lacking too,... I agree, the soil pH should be checked first before upping feeds! What's your water source and pH? ... you meter, did it dry out, or is it hazed over on the bulb electrode (dirty)? This can make it FUBAR, and not hold calibration well,.. it might be wise to double check, with both 7.0 and 4.0pH calibration solutions,...
just for a crude test, water as normal, no feeds until you get a cup or so of run-off, then test that for pH,... any chance you have a TDS or EC meter? getting some sort of clue about the pH in there is critical to deciding what the next step is,...

 

[Renaissance Redneck]

guys,..

..symptoms look mostly like N defc. to me, likely from the lack-of during veg', very little stored,... but the weak bud set say P-K are lacking too,... I agree, the soil pH should be checked first before upping feeds! What's your water source and pH? ... you meter, did it dry out, or is it hazed over on the bulb electrode (dirty)? This can make it FUBAR, and not hold calibration well,.. it might be wise to double check, with both 7.0 and 4.0pH calibration solutions,...
just for a crude test, water as normal, no feeds until you get a cup or so of run-off, then test that for pH,... any chance you have a TDS or EC meter? getting some sort of clue about the pH in there is critical to deciding what the next step is,...

Spot on as usual, and explained better than I ever could

 

[flyinhawaiian]

Sorry I took so long to get back on this. As some on here know my wife is in year 2 of her battle with cancer and we had some setbacks this week.....Ok so I got my PH pen all taken care of and WILL stay on top of it for now on. I did not check the PH in the soil (wasnt able to) so I went ahead with another round of nutes at 6.0PH. The leaves are no longer turning yellow and the plant has started to "green up" a little. The existing buds are looking better and some new ones have formed. Seems everything is getting back on track (I hope)........Thanks for everyones help!!

 

[Waira]

:smoking: good to hear Flyin'! no need to pH that low, too close to out of range,.. stay at 6.5-ish,... Sorry to hear about your wife mate -- have you explored the Medical sections here? Root and Eekman, Red here, are some key peep's to get with on this!

 

[Renaissance Redneck]

Sorry I took so long to get back on this. As some on here know my wife is in year 2 of her battle with cancer and we had some setbacks this week.....Ok so I got my PH pen all taken care of and WILL stay on top of it for now on. I did not check the PH in the soil (wasnt able to) so I went ahead with another round of nutes at 6.0PH. The leaves are no longer turning yellow and the plant has started to "green up" a little. The existing buds are looking better and some new ones have formed. Seems everything is getting back on track (I hope)........Thanks for everyones help!!

Glad things are bouncing back, Flyin! And @Waira is right, 6.5 is a much better number to aim for.
And I'm very sorry about your wife. You should definitely check out the medical forum.
https://www.autoflower.org/#the-medical-forum.79
In particular, read everything you can about pH and the body, and the benefits of magnesium chloride.
As a cancer survivor, I consider my remission to be largely from what I learned from people like Root and Mossy.
Just know this : we are less different from the plants we grow than you might think. Just like our beloved medicine, pH is a critical component to our health.
Karma to you and yours, feel free to tag or pm me if you need to talk or have any questions.