Chemdawg4 - One out of 4 is sick. Other girls look great

I have 4 girls going, 2 chemdawg4 and 2 007 OG Kush.

Indoor Grow under 2- 400w MH
Temp has never been above 82 with good airflow and circulation
They are growing in 50/50 FFOF and Royal Gold Tupur
I water Once a week till I see runoff and once a week a light water to supplement.
I have been using straight tap water (no nutes), as the soil is quite "hot" as is. (All of the other girls are getting plenty of what they need)
EDIT: I'm in Denver, so Im using Denver Tap water, which is known to be great for the girls.

Everything looked good and normal until a couple days ago. I was traveling and a friend sent me a pic. (Pic one) from last Tuesday, the now sick girl is the one in the front left. When I got home yesterday, everything was dry, as expected, and looked "okay-ish" to "not-so-well". I watered all of them with a dose FF "Boomerang" as prescribed on the bottle.

Now this one girl is not looking so good at all. I tried to look at the pictures and have done an immense ammount of research on this throughout the years but could really use an experienced eye to point me in the right direction.

Thank you for your time.

This is sort of a shot in the dark, but maybe a potassium or phosphorous deficiency? Red stems can be a sign of a phosphorous deficiency. CAN be, not always is.
Then again... the rest of your plants don't look deficient.

Great job on vegging those plants; even the deficient one is a beauty! It looks like it's experienced slight heat stress as well as indicated by the coupled leaflets on your compound leaves. It also could be a pH issue manifesting nutrient lockout of potassium; aesthetically that's what the deficiency resembles with the pattern of discoloration.

i agree with cannabrain there definitely looks like a potassium def to me ive had a similar prob just feed it some high in potassium also make sure your ph is 6.5 6.0 to rule out ph lockout

I have grown ChemDawg4. These are growing Superb. When I grew them they were inside, 25 Gallon buckets. They grew so tall ( Under 1000 Watts ) What I notice when the season was done was the roots grew thick and fast. If the roots get bound it causes weird issues with intake of nutrients. So I am not saying its not potassium deficiency. Just a thought I would throw out their.
They look great! keep up the good work. Give Chemdawg4 Great name!

Thank you for all of the information y'all. Things look to be turning, even if ever so slightly this morning.

One thing to note...

- I've had the leaf curling/disfiguration in new growth for about the last month, I think I built the soil up JUST a bit too strong.. So that's not a new symptom.

After researching the advise given, and comparing to picture charts etc.; I concur that the leaves are most likely showing signs of potassium deficiency. It's hard to really tell just 36 hours after the Boomerang/water feeding, but new growth IMO looks much better. That being said... I ponder why only one of the gals showed signs of the deficiency.

What I know:
- The soil is "hot" and has all of the necessary nutrients required for growing (as shown by the other 3 plants with healthy growth, and that OOFO and Tupur are known for this, and I supplemented with a nute solution once a few weeks into veg)
- Runoff ph had been being low 5.0 - 5.5 about a month ago so I've been ph'ing my water to 7.0; Ph on Fridays runoff was 6.3.

I think I have possibly been letting the soil get too dry between waterings...
- This could cause stress/lockout in one girl and not the others.
- The components of FFOF and Tupur are "living" organic mediums and require a healthy environment for the micro-organisms to flourish. (I know nothing about this other than things Ive read and been told, but it makes sense to me)

It appears that I may have finally worked my way through a Ph issue I have had since week 1 (which has been odd since the soils I used are supposed to be Ph prepared). Assuming things keep progressing in this positive direction, I will continue to water with the Boomerang Comeback Formula until everything is back to normal. I will not add any additional potassium other than what is in the Boomerang; I'm running with the lockout theory so I don't want to add too much and go the other direction once the roots are healthy. I speculate that I missed the early signs of the potassium deficiency because they were being masked by the mild "nute burn" that gal sustained from my "nute supplement" a few weeks back.

I have just one or two questions to ask as a follow-up....

Can a Ph related lockout issue only "lockout" one specific nuterient, like specifically potassium, as we are discussing here?
Can I have a lockout of potassium while the girl absorbs an abundance of nitrogen?
Will I see any "healing" or repair of the damaged leaves? or should I only be concerned with the look of new growth?

Thank you as always!

1: No, pH locks will involve several nutrients at a time to different degrees. Different nutrients are effected when pH is low then when pH is high to again different degrees.

pHing the run off does NOT give you the pH of the soil. Yes, soil does self pH, If you care for it, keeping those bio's happy.
Soil will swing pH to one way when watered and it will swing back as it dries back out.
Adding back some bio's when using a synthetic IS needed about once a week to help keep them there.
Adding a bit of dolomite lime into your soil mix at about 1/2 cup per cubic ft of mix can help even the best premix soil control pH swings better.

2: Yes

3: N def will repair with treatment. Everything else will not. You have to look to the new growth there.
Soil will express in 5-7 days and 3-5 for hydro applications.

P.S. Every Chem strain I have run has always had purple stems...
I NEVER make nutrient calls on stem colors as to many have purple stems as a trait. Not reliable.

THE DOCTA SLINGIN MAD KNOWLEDGE!

Thank you very much for the info! I love those cool purple striped stems, definitely not to be confused with a symptom in this strain!

I really cant say if she is making any progress... and the other chemdogg4 is starting to show beginning to intermediate signs of deficiency as well.

So given answers to 1 and 2, It sounds like I should be safe to add Fox Farms "Root Drench".8-.1-.3 in addition to, or even better, in place of the "Boomerang" 2-.2-.3.... I dont want to keep adding the additional nitrogen the boomerang provides just to get the bios. A comparison of the active bios between the two shows the "root drench" has the kitchen sink in terms of bios...

(The Doctors answers prompted me to do some more research )

Which got me thinking that the "boomerang" wasn't such a good choice after all. The soil had been right where I wanted it with the N. So adding the 2.0N in the boomerang might have been enough to stress the girls into a "excess nitrogen / potassium lockout"

So, based on today's research, I plan on watering with the Fox Farm Root Drench (for the bios) instead of the boomerang.

Still pondering though...

- Is there a chance that the girls may actually be using all of that potassium provided in the FFOF/Tupur and the Boomerang nute?
Would it hurt to add a silica 0-0-3 product to the water/root drench feeding?
Would that amount of Potassium be detrimental if there is already an abundance in the soil?

I guess I know y'all cant give me the all the answers, I'm just kind of soundboarding! Thanks for the ear.

Im going to flush liberally again in the morning with water (6. and root drench. I;ll update with pics when I see and real visible change and I'll look forward to the boards continued words of wisdom.

Cheers!

Your plan sounds solid 4Grow; silica would be beneficial to add as it ameliorates stress and makes your girls more resilient to stressors in general; it also increases the size of the plants' cell walls with noticeably more tensile strength than an untreated plant. That additional three percent should be fine, cannabis utilizes an abundance of potassium during its life cycle, just ensure your NPK ratios are dialed in. I'd recommend the Dyna-Gro Protekt brand; it's the shit and I've never had any problems implementing it in my feeding regimen. Keep us updated, that's a connoisseur strain you've got!

Okay, The girl(s), now 3 out of 4 are showing potassium deficiency in different stages, I imagine that #4 is right on their heels.

For starters, I took my month old bluelab ph pen into get calibrated today and they told me my unit was all messed up. They replaced it on the spot... So WHO KNOWS what I have been doing to the ph levels as I have been watering?!?

I did a 4 gallon per plant flush today with....
Gro-tek Pro-Silicate (0-0-3) at 1/2 tsp / gal
FF Root Drench
1/3 strength FF Grow Big

I decided to add the very light feeding of Grow Big after some internal debate... Both my guy at the grow store AND the nice lady at Fox Farms Product Support team convinced me that the FFOF/Tupur combo is not as "hot" as I initially estimated, and that I need to at least start introducing the girls to the nutes. gen Also, more research has shown me that only ammonium nitorogen causes nute lock; not the predominant source of nitrogen in the FF line of nutes. Since plan on moving into flower as soon as they are healthy so they tell me its best to start ramping them up.

Anyhow, I am more confident than ever that there is a Ph problem with the soil.

Ill keep y'all updated

the gals are looking good. Im gonna give them another couple days to recover and then these girls are getting put on timers!

You're sure to have a bountiful harvest; beautiful! Did you happen to record a reading of the run-off? Haha, I had a similar experience with my Bluelab pH pen recently, it decided to fluctuate an entire pH point after a stable initial reading after a routine calibration and I responding by rendering it useless on some fine concrete. Regardless, I bought an identical model; they really are the premier pens on the market, but you need to be religious with their maintenance. I should just keep a good old pH testing kit handy.