Potassion K deficency causes...input needed

[D350]

My SS and Grand Daddy developed pretty severe K deficency.
I'm not sure wich way to go, add more nutes or flush...some insights needed, thank you...

-Humidity and temps are in the zone, so that is not it.
-Canna Terra Vega in veg, now on AN Connosieur...feeding carefully, below half the reccomended doses.
-third week of flower.
-Soil with some clay, perlite and lime.
-20l pots, SS ran away a bit, 1,2-1,6m high. Grand Daddy normal height around 80cm...

Possible causes for def.:

- I overlimed the soil (battling high Ph from the start wit really low Ph watering). Could too much lime did this?

- Nute burn...but my runoff EC is really low 1-1,2, ph 6.6.-6.8 (lime is doing its job...ph water-in in low 5). I upped EC to a 1.6-1.8 with the last feeding of EC1,5. There were no real change, maybe a bit to the worst, but not much.

- Leaves are dark green, again sign of overfert...and wilting up in a V shape. But no signs of Mg def.


which way to go? Add K or Add nothing/flush?

Thank you for your help.

 

[D350]

Sooo, went medium, added 0,6EC fertilizet, no bug change. Measured runoff at 1,5EC, 6.6ph.
Should I go full strenght next time?
Thank you

 

[D350]

Sorry, no big change, stupid small phone keyboard

 

[DrDee]

D350,
Hard to know where to start. Too many newbie mistakes. Why are you trying to micro-manage soil ph? How are you even doing this? With runoff ph?

So thinking logically, you are giving flowering nutrients which are high in K...and yet you have K deficiency symptoms. So the only answer is that something is preventing proper absorption.

I say flush the hell out of them...then back off on the low ph watering. Stop checking runoff ph and just let the plant alone to grow...
DrDee

 

[milkyjoe]

No disrespect but do you have a pic of the K def, or at least a description of what you see. With bagged soil and/or store bought nutes I really suspect something else.

And yea, do not pH water that low...that does not fix anything. It just burns root hairs in before the soils alkalinity buffers it.

 

[vostok]

Pics please ....you intend to add more but don't know whether to flush first ....?

Always .............Always ............Flush first then wait 2 weeks, then feed again 50% less or until you see an improvement

 

[D350]

Pictures

Pictures

Thanks for the input, noted.
I'm basically deciding if I flush or up the nutes...
as the runoff says more nutes, but I'm not so sure.

Can too much lime block the K?

Pictures included, hope this helps deciding...

Thank you all very much for help

 

[DrDee]

D350,
You've asked about the lime issue. First...what sort of lime was it? I'm assuming Dolomite but it could have been regular old garden lime.

And regarding runoff. With soil. it's a very crude measurement and mostly is useful to determine of your soil is toxified from excess nutrients. Soil runoff for ph is not particularly useful and if you're chasing ph using runoff...well that's at least half your problem.

You do have signs of K deficiency...but lK deficiency is very uncommon unless from a lockout.
DrDee

 

[milkyjoe]

All of the major cations antagonize each other...Ca, K, Mg, Na, and NH4...so if you have an excess of any of those the others will not be taken up properly. You do indeed have a K def causes by a lockout from too much lime.

The only way to fix it is foliar...you need to spray some K...either an amino complexed K like Albion or JH Biotech or K Sulfate with some fulvic acid and a spreader.

You are not going to fix it with that soil alone until the plants use up enough Ca.

I would add a couple of you tube videos but for some reason I cannot access it right now...look up John Kempf sap analysis and Nova Crop Controls when you get a chance...excellent videos that explain this very well.

 

[D350]

D350,
You've asked about the lime issue. First...what sort of lime was it? I'm assuming Dolomite but it could have been regular old garden lime.

And regarding runoff. With soil. it's a very crude measurement and mostly is useful to determine of your soil is toxified from excess nutrients. Soil runoff for ph is not particularly useful and if you're chasing ph using runoff...well that's at least half your problem.

You do have signs of K deficiency...but lK deficiency is very uncommon unless from a lockout.
DrDee

Thank you.
I used agricultural lime, fine powder CaCO3 > 96%
Should be slow releasing...?

I know runoff is not a sure thing, that is why I'm asking what to do next...puzzled.
I guess no Ca in my watering for now - RO water + light nutes?

Hmhmh...

 

[D350]

All of the major cations antagonize each other...Ca, K, Mg, Na, and NH4...so if you have an excess of any of those the others will not be taken up properly. You do indeed have a K def causes by a lockout from too much lime.

The only way to fix it is foliar...you need to spray some K...either an amino complexed K like Albion or JH Biotech or K Sulfate with some fulvic acid and a spreader.

You are not going to fix it with that soil alone until the plants use up enough Ca.

I would add a couple of you tube videos but for some reason I cannot access it right now...look up John Kempf sap analysis and Nova Crop Controls when you get a chance...excellent videos that explain this very well.

Great videos. Thank you..
Can I foliar feed normal K fertilizer, or it needs to be special form for foliar, as you suggested?

Thank you!

 

[milkyjoe]

You should be able to find K2SO4 locally The SO4 will help in converting nitrates to protein also...a really good thing. What did you have in mind to spray?

I actually prefer your situation. That way you know there is plenty of Ca to build cell walls, you will have less insect and disease pressure that way. And you can just add K as needed.

 

[UgoTiraL'Altro]

I think i'm in your same situation but by adding calcium to the irrigation water cause i have a water softner that filter off all calcium and mg, but maybe i added too much camag, ill add photos now... Maybe mine is much severe...

 

[theother]

I think i'm in your same situation but by adding calcium to the irrigation water cause i have a water softner that filter off all calcium and mg, but maybe i added too much camag, ill add photos now... Maybe mine is much severe...

Water softener a are pretty much unacceptable man, you need to get the water before it is softened. A water softener works by using with salt or potassium chloride to charge a resin, the water flows through the resin and the calcium magnesium, and other stuff is chemically attracted to the resin and salt combination. As the calcium binds to the resin it displaces the salt or potassium into the water. Really the last thing you want in your solution is an unknown amount of salt or potassium chloride.

 

[UgoTiraL'Altro]

here is some photos

 

[UgoTiraL'Altro]

i know, i started using a RO water but still cutted with the softed water, i'm actually working to fill up a tank of 50 liter of good water from the fountain and use it to cut the RO... that can work?

 

[UgoTiraL'Altro]

how can i solve?

 

[theother]

how can i solve?

I am sure not all of your home is hooked up to the water softener. Really you will have to investigate, but my guess would be any outside hose bibs are not hooked up to the water softener. Usually they don't plumb the whole house into the softener. I assume by getting water from the fountain you mean like some kind of public drinking fountain or something? Don't use stale water if it actually is like a decorative fountain or whatever. Also it is best if the RO isn't plumbed in after the water softener. All of the salt of potasium or whatever will just shorten the life of the membrane and filters considerably (Im guessing here, but I think it is a good guess. It could also be possible that the salt would be directly proportional to the calcium that it displaced)

 

[D350]

Thank you all for your input.
Just an update: they were underfed. Runoff ec was just too low and ph was ok, to have a lockout. I watered them a couple of times with very low ec, and they started to yellow, that was my clue.
So, full strenght sorted it out, altough not in full, as I'm 2weeks before harvest now and I'll soon start to flush...

Thank you all.

 

[k-grower]

that could be environment issue, i had supersilverhazes, they wilted from too much air circulation and had those v shape issues, also hot spots can make that spot yellowing as i don´t see it affecting hole plant.
you check the plants from mites, what is relative humidity on that space, any fans blowing on that spot? or some alumine foils added in room?