Confirm my Diagnosis Please?

[MonkeyDragon]

Hello all. I have some nutrient issues. I have been pretty thorough in my search for leaves with exactly the same characteristics, but I can't be sure. I'm a semi-noob - everything's been going great. Until now. Much appreciation to all who look, and help. :cool:

Shared elements between two plants in photos (below):
3x5 tent
300 watts fluorescent lighting
FFOF 4/1 Perlite
Distilled H2o
Blue Planet 3-part (I feed both these plants essentially identically)
400-500 ppm
CaliMagic at 1/4 strength
Ph 5.9-6.1 (I measured a 6.1 runoff, so I think I'm good)
73-79 degrees, 40-50% humidity


Plant One:
3-foot mother/OG Kush/from clone/7-8 mos. old/Smart Pot
This plant is showing darker color in the center of the leaf and lighter on the outside.
I think this looks like early Phosphorus deficiency. Can anyone confirm?

Plant(s) Two:
5 Teens/3 Varieties from Seed/SAGE, Moby Dick, OG13/3 months old/Air Pots
These plants, especially Moby Dick, are showing almost neon yellow growth
This seems like overall nutrient deficiency, or a more advanced Nitrogen deficiency?

I'm thinking I may just be underfeeding all my plants as they get older. My last watering was pure water only, maybe that was a mistake. I do not foliar feed. I would probably be confident in going in and giving them a good feeding, but I saw one post that suggested neon / bright green leaves was Nitrogen overdose. So doubts remain.
I have learned a great deal from this website. My research here has kept me problem-free for a few runs. I look forward to the day when I have enough knowledge to share back.

 

[Seamaiden]

Overfed N to my eyes, the leaf depicted much more resembles a Mg-, too. I see reddened/purpled petioles, if it's not strain-specific then it could indicate an early P-. I would first raise the pH, and switch to a mix of tap & distilled as I feel distilled is actually too clean. Or you could use RO water that's low EC instead of almost pure water. I would not feed more here, for sure.

You could top-dress a wee bit of dolomite lime, but I'm thinking you can get the pH up just by using tap water in the mix. They're not hungry, they're maladjusted. Like teenagers who eat nothing but microwave burritos and Coke.

 

[MonkeyDragon]

Thanks Seamaiden. I'm glad I checked with you all first. I can definitely change my water without issue. I don't know if this changes your thinking but the petioles you see are in fact specific to that plant. I have grown it three times now and each time I worry about the purple petioles and try to fix them. They never go away. So I guess that confirms your diagnosis even more - it's not P- so I must have over fed.

Can you explain the Mg- issue? How do I fix that and will my tap water addition change that situation?

Thanks again for reviewing.

 

[MonkeyDragon]

Well I came down to my spot today and it would seem you were completely correct. Though some of the bright green has gone away (maybe because my last watering was only water), some leaves are now curling. I've gone with an RO/tap water combo and added CaliMagic, but nothing else. Hopefully they'll start turning around. Here's a pic of curl today:

Let me know if I'm making matters worse in any way. Cheers.

 

[Botanikos]

Had similar issues and found that early growth yellowing most likely is an N issue
The Dark green and purple stems turned out to be a Phosphorus issue

Try to correct those and 1-2 weeks you should see an improvement.
Foliar spraying some N could make things quicker with the N issue.

my $.02

Good Luck!

 

[MonkeyDragon]

Thanks once more for your thoughts Botanikos and Seamaiden. Things have turned around for the 5 teens. Since the mother plant shows minor symptoms, I'm waiting for her next watering to correct the balance. For the teens, I semi-flushed them with low EC water and a pinch of CaliMagic. I tested the runoff to see where I was at, EC-wise. Lets just say I'd rather not tell you what the reading was. I guess I'm a serial over-feeder. Working on it!

Below is a shot of happier teens one day after flush. Cheers.

 

[Seamaiden]

You can get Epsom salt (MgSO4, which gives you both Mg and S, both are necessary to plant function) and use it at a low rate either as a foliar feed or root drench. It's highly mobile, so you can correct all but the worst deficiencies using it either way. I start at 1/4tsp/gal for either method. Using as a foliar means you aren't adding more stuff to your feed, though you may need to lower it a bit still.

I still recommend getting a separate Ca product and using that, aim for a 3:1 ratio Ca:Mg.