"N" def and "p" tox? or def?? w/pics

4xfish

Well-Known Member
18 days since switiched to 12/12
i have 3 sweet skunk, this one is the only one doing it. only the top of the plant is showing the problem



this is bubba i think its a phosphorus problem. the problem leaves are from new - old leaves and bottom to top leaves






can anyone confirm this? or have any other ideas??
 

Dennis Stein

Active Member
Could be numerous problems. What first comes to my mind is possible aerobic conditions on the bottom of your container causing N lock out. Awfully large container for the size of plant...makes it longer for dry down times that are beloved plant loves so much. Then I start thinking, how long was this plant in this container before you flipped the lights? Did you flip the lights to fast after your transplant - where the roots didn't get a chance to find the new soil and food? This could also easily cause you to have a wet soil all the time. Look for the drooping of lower leaves as a sign to water. Just because your top is dry doesn't mean your bottom is dry. I like to mist the top of my mulch layer on top every morning as this keeps my top layer fairly moist and gives my bottom layer a chance to come off wet. Keeps my top dressings breaking down also.
Your next problem is your plant is getting ready for senescence. It's going to start yellowing anyways and start using it's built up N in the leaves as long as it's not a longer flowering sativa. So don't keep throwing a bunch of available N in the near future. Like after the 30 day mark on a 60 day strain. Little N is OK, but too much N will hurt your resin production and bud growth. Will cause your plant to put on vegetative growth instead of reproductive growth.
 
i disagree with dennis..

I think the container is fine for its size

The leaves curling up is a sign of potassium deficiency..Its weird how its affecting top growth the most..

I dont see that often

Flush with ph'd water
 

bud nugbong

Well-Known Member
Im no pro, but those closeups look like what I call "nute burn". when leaves edges crisp up like that. Spartacus seems pretty sure, so check your feeding records and you should be able to tell if you went hard or soft.
 

Dennis Stein

Active Member
We know it's a deficiency or toxicity problem. What I should have said is this - "make sure you watering habits are down pat". I like to water twice, waiting 1/2 hour to an hour before my second watering (with some runoff - I want to make sure the medium is thoroughly wet with no dry pockets). First watering is done with plain water and the second watering gets the food/teas. Then wait for signs of droopy leaves before watering again. Usually 3 days for my 1 gallon containers and 5 for my 3 gallons.
If these conditions are meant and you feel you didn't mess up a watering, then go on to the next step - diagnosing a plant deficiency or toxicity. Maybe you need some light nutes or maybe you should flush. I don't know. Only he knows what's in his soil and what's in his food. I don't even know if he's feeding his plants with synthetics or if he's all organic. And then there's his water source, another important factor we know nothing about.
Raising your plant off the ground and running some kind of wick through the bottom holes will help suck some moisture out of the bottom if you feel your container bottom is staying too wet. Transplanting again at this stage is not an option.
I don't go changing my motor when my car doesn't start. :eyesmoke:
 

4xfish

Well-Known Member
They are in 3 gallon geopots. And I make sure they almost dry out before I water/feed again. I know I am not over watering them. It takes about 5 days for the pots dry out

Water/feed water ph-5.8
Soil promix hp
Nutes- Alaskas fish fert(5-1-1)
Alaskas more bloom (0-10-10)

I'm using a mix of the two so I can get some "n" in the feeding water.

My last feeding was at 1200ppms ph of 5.8

I was away on holidays for a week and got my gf to give the plants pre ph'd water(5.8)(no nutes) when the pots got dry. Only 2 liters. The 3 gallons geopots take 5 liters for the proper amount of run off.

If u think its a "p" def, then it has to be Locked out for some reason, no? Because my nutes have plenty of "p" in it....

What about the sweet skunk... Just keep giving a little bit of "n" and hope for the best? I know not to over do the "n" cause it's starting to flower...

--------the first 2 pics are a different plant than the pics with the leaves. Ill get some more pics when the lights turn on
 

4xfish

Well-Known Member
What r your thoughts on this, say ur soil is saturated with food--- way to much! Instead of a flush, u just water with ph'd water to dilute the nutes in the medium so u dont end up shocking the plant when doing a proper flush (double water- pot size)
 

Dennis Stein

Active Member
I like your fish fert for the first half of flowering. Then I switch to organic gem (3-3-0) for weeks 4-6. We know that a plant can store enough P to take it through half way of flowering and that a plant does not like a lot of liquid P all at once. That more bloom I'm not too familiar with, but I can say with those numbers, I wouldn't want to use it early in flowering - maybe light doses second half. Use clean water source also with no chlorine or chloramines. "The fungal micro guys are one of the main forces when it comes to high P uptake by your plants, especially the Mycorrhizal fungus." -REv

And where is cal/mag? Maybe you don't need it if you're using tap water. But if using tap water, you're killing the friendly micro guys.

https://www.rollitup.org/general-marijuana-growing/205097-importance-p-hosphorus.html
 

Dennis Stein

Active Member
I have some P in my soil mix but like to top dress with a little (0-5-0) bat guano and alfalfa meal (2-1-2) like say 10-14 days into flowering, along with a pinch of feathermeal and or blood meal. If you feel your soil is on the acidic side and has a low pH, than stay away from the guano as this will cause your pH to dive even further. My next choice would be Soft Rock Phosphate (powdered) (0-2-0) as this will help raise your pH. Throw in a pinch of oyster shells if you feel your mix is light in Calcium.
With these top dressing, you don't have to worry about pooring in all your P and some of the other nutrients all at once. We're getting a nice slow steady release of these nutes which the plant likes.

30 days into flowering I'll top dress again with a little kelp meal (1-0-2). No more available N from this point on. I'll have just a little N in my teas to keep the friendly's happy - kelp meal, organic gem, fox farm big bloom. Along with some high P bird/bat guano (with N-P-K ratios of 0-5-0 or 1-10-0) and a tsp of molasses. Maybe some cal/mag if I feel the need.

Hope this helps!
 

Dennis Stein

Active Member
Root's organic Nitro Bat Guano (9-3-1) w/8% Ca is one of my favorite additions to my teas up to the halfway point of flowering. I opt for Organicare Pure Granular Growth (6-6-5) w/8% Ca as a soil amendment - especially when I do my last transplant before flowering (about 10-14 days before flipping the lights). I like a little feather meal on the bottom of my containers too as I feel my plants stay green a little longer with this slow release N. Some other additions to my container during last transplant would be All Purpose (4-4-4) w/4% Ca, Bulb food (3-8-8) w/9% Ca, Organicare Pure Flower (1-5-4) w/6% Ca, Kelp Meal, and EWC's. These nutrients are to be used in localized zones during transplant (DO NOT MIX GLOBALLY), with the exception of the Earthworm castings. Lots of Ca coming into the picture. Some of these nutrients have a little Mg in them, but not too much. I bring some Mg into the picture with my molasses and my cal/mag. This keeps my Calcium/Mg ratio high where I like it.
I feel no need to top dress during veg. Plants don't need it with the soil mix. Just 2-3 high N veg teas and/or all purpose teas to keep the beasties happy. PPm's rarely exceed 600. If you plan on vegging for longer than 60 days, than you may consider a little all purpose top dressing or some high N guano. Perhaps some feathermeal and/or blood meal.
 

propertyoftheUS

Well-Known Member
Flush it with ph'd water and then feed with 1/2 strength nutes, also are you using cal/mag? Looks like you definitely have a Magnesium lockout
 

4xfish

Well-Known Member
So the sweet skunk was an easy fix just have it a little more nitrogen and the green is coming back but not lots. Gonna start another tread for the others.
 
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