Potassium toxicity?
- Thread starter Forte
- Start date
Grandpa GreenJeans
Well-Known Member
Well I see a few things wrong.
1. I see solid purple stems and green striped stems. Chances are if you striped and solid it's a symptom and not genitic. This is a tell tale sign of Phosphorous deficiency. If you don't fix it before flower, your yeild will greatly suffer and you will loose fan leaves. Starting on the lowest, oldest ones first, then progressing up to the bud fans. P is a immobile element and moves very slowly within the plant and even slower in the media.
CAUSES:
Possibly low Phosphorous
Too frequent watering
pH is not in range
Root problems
Bugs
Lockout from high sodium
2. I also see burnt fan blade tips. This means that the plant has enough NPK nutrient and anymore will result in further leaf necrosis and lower total viable surface area for the leaf to conduct photosynthesis. Also this signifies a buildup of TDS and lockout is most likely to follow from high salt. Flushing is the only recourse to corrective action.
3. You have necrotic lesions in varying locations on varying fan leaves. This is most likely a symptom of poor pH management, conjoined with high sodium levels.
4. I see interveinal chlorosis on other fan leafs. The yellowing between the veins is a clear sign that you have a magnesium deficiency. Epsom salts (magnesium sulfate) @ 1tbsp/gallon used in a foliar fashion will fix this very quickly. Alternatively you can use dolomite lime as a top dress or crush up and add to watering schedule. This will take some time to work and is preferably done at the soil mixing stage.
CAUSES:
High calcium
Calcium deficiency
High nitrogen
Poor pH
Low magnesium
My advise..... add some lime as a top dress (1tbsp/trade gallon of soil), and flush it in with 3x's soil volume of water. Make sure to adjust your flush water to 6.5pH. Stop the flush when the runoff pH is 6.5. Don't feed for at least 4 days. This is completly dependant on what the runoff values are, plant size and age.
Hope this was helpful.
1. I see solid purple stems and green striped stems. Chances are if you striped and solid it's a symptom and not genitic. This is a tell tale sign of Phosphorous deficiency. If you don't fix it before flower, your yeild will greatly suffer and you will loose fan leaves. Starting on the lowest, oldest ones first, then progressing up to the bud fans. P is a immobile element and moves very slowly within the plant and even slower in the media.
CAUSES:
Possibly low Phosphorous
Too frequent watering
pH is not in range
Root problems
Bugs
Lockout from high sodium
2. I also see burnt fan blade tips. This means that the plant has enough NPK nutrient and anymore will result in further leaf necrosis and lower total viable surface area for the leaf to conduct photosynthesis. Also this signifies a buildup of TDS and lockout is most likely to follow from high salt. Flushing is the only recourse to corrective action.
3. You have necrotic lesions in varying locations on varying fan leaves. This is most likely a symptom of poor pH management, conjoined with high sodium levels.
4. I see interveinal chlorosis on other fan leafs. The yellowing between the veins is a clear sign that you have a magnesium deficiency. Epsom salts (magnesium sulfate) @ 1tbsp/gallon used in a foliar fashion will fix this very quickly. Alternatively you can use dolomite lime as a top dress or crush up and add to watering schedule. This will take some time to work and is preferably done at the soil mixing stage.
CAUSES:
High calcium
Calcium deficiency
High nitrogen
Poor pH
Low magnesium
My advise..... add some lime as a top dress (1tbsp/trade gallon of soil), and flush it in with 3x's soil volume of water. Make sure to adjust your flush water to 6.5pH. Stop the flush when the runoff pH is 6.5. Don't feed for at least 4 days. This is completly dependant on what the runoff values are, plant size and age.
Hope this was helpful.
MistaRasta
Well-Known Member
Definitely looks like too much nitrogen locking out mag/phosphorus. Cut back on the nitrogen next time
Forte
Well-Known Member
What might this be?
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MistaRasta
Well-Known Member
Looks like a straight up phosphorus deficiency to me. @Grandpa GreenJeans was right on the money, as with a magnesium deficiency you'll lose the chlorophyll in the veins of the leaves in the early stages.. What's in your medium? How much of each amendment is in your medium? How much water are you giving it? Are you using bottled nutrients?
It's likely too much nitrogen but as grandpa green said, it could Be a multitude of factors, without knowing your setup and what your procedure is I can't come to a conclusion
Forte
Well-Known Member
I grow in sphagnum peat moss. Water every 2 days. Temp is around 63 deg. I give it a weekly alfalfa meal tea.Looks like a straight up phosphorus deficiency to me. @Grandpa GreenJeans was right on the money, as with a magnesium deficiency you'll lose the chlorophyll in the veins of the leaves in the early stages.. What's in your medium? How much of each amendment is in your medium? How much water are you giving it? Are you using bottled nutrients?
It's likely too much nitrogen but as grandpa green said, it could Be a multitude of factors, without knowing your setup and what your procedure is I can't come to a conclusion
1/2- cup oyster shell flour
1- cup gypsum
1/2- cup azomite
1/4- cup basalt rock dust
1/2- cup bentonite
1/2- cup crab shell meal
1/2- cup fish meal
1/2- cup High P bat guano
1/2- cup alfalfa meal
1/2- cup fish bone meal
1- cup kelp meal
1/4 cup granular humic acid
1/4 cup diatomaceous earth
1/2 gallon 3mm biochar
MistaRasta
Well-Known Member
Gotta lot in your soil. A good amount of these products are redundant as you have everything you need in a third of those ingredients. I'd cut out the weekly alfalfa tea which is supplying ALOT of nitrogen.. With how many ingredients are in your mix you should only be giving the plant water..
Your temperature averages 63 with the lights on? If this is the case you need to find a way to raise your temps, temps alone can specifically cause phosphorous deficiencies. If this is the case it's getting even colder at night I'm sure and that just so happens to be when your roots feed..
One more thing, with your temps being so low are your pots somewhat dry when you water them?.. not soaking or anything..
Forte
Well-Known Member
Yes, temperatures are 63 deg with my t5 light on. I noticed that when I cut back on watering, the new growth of stems are turning green again. Maybe overwatering was causing phosphorus deficiency? My pots are always moist, I never let them get dry.
MistaRasta
Well-Known Member
It's Very hard to come across deficiencies and lockouts caused by problems within your rhizosphere when dealing with organics. Even with all those ingredients as long as you let your soil cook, and have a good foundation of micro life, you should be fine..
Overwatering is most likely the culprit as most problems in the grow room are environmental.. Cut back watering to every 4 days until your temps go back up and you should be fine. It's ok to let your soil dry out somewhat, just always keep the top layer moist
Midwest Weedist
Well-Known Member
In my experience, overwatering. I just mixed up a new soil mix with rotted wood and a clay based humus and didn't mix in quite enough aeration and bam, this is exactly what I saw. Every time I've thought I had an issue with a deficiency or toxicity in organics it's always been environmental, most of the time from overwatering or cold night temps. Food for thought!
whitebb2727
Well-Known Member
Spagnum holds water and is acidic.
greasemonkeymann
Well-Known Member
similar to my experiences as well, I've always said the key is getting oxygen rich "humid" soil rich in humus to get those roots to explode.
I have probably close to 40% maybe even 45% aeration in my soil, but of all sorts.
But you are so right.
probably 75% of the time the pictures that match "this" deficiency or "that" toxicity is in fact just poor soil construction, or poor watering techniques.
Cannabis likes fluffy, aerated, "humid" (not WET), humus rich soil, it really doesn't need as much nutrients as people are giving it, at least not organically.
the other one is being rootbound. I see that one a lot too, and then people start mucking with calmag, ph up/down, this nutrient, that nutrient. Which undoubtedly makes it worse.
when it simply needs more room.
greasemonkeymann
Well-Known Member
yea, but he's adding gypsum, crab meal, and oyster flour.
Peat is a good growing medium, very good CEC, better than coco
whitebb2727
Well-Known Member
Except the holding water part. The stuff stays too wet. I use it in outdoors and had plants hold water in 100 degree heat. I just can't see that much spagnum good.
Not only does it stay wet it goes hydrophobic when it dries.
greasemonkeymann
Well-Known Member
Ahh I see your issue with it.
I loved using peat, but I use a WHOLE lot of varying aerations.
It's still in my mix today, I've just diluted it down with leaf compost so much it's hard to see anymore.
I think the water retention thing is a valid point though, but I never personally had a problem with it.
-edit-
stoner moment
just realized he doesn't have any humus in this mix.
That's something i'd address
you are right, pure peat is too much
Midwest Weedist
Well-Known Member
Couldn't agree more! I've got about 30 percent aeration in my mix now and I'm planning to bump it up a lot after this run. Native clay humus and rotted wood hold a crap ton of water lol
greasemonkeymann
Well-Known Member
yea they do, but that's why they work so well too, that improved CEC.
When I first started using the rotted wood chunks I noticed I watered MUCH less than normal.
like probably 40% less.
I really love the leaf compost, that stuff almost works like aeration also, doesn't compact as easily as peat does too
Midwest Weedist
Well-Known Member
Can't wait to get my leaf compost started this spring. I've got like 10 houses who are giving me their bagged leaves!! That stuff is magic, almost as amazing as vermi.