Is this a potassium deficiency?

What defencency do I have

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RussianReaper

RussianReaper

Member
Hey guys I need some expert advice here as I am no expert!!! This is a feminized hash plant that started Turing yellow and and a few brown spots. I am growing in a tent with a 600watt led the plant is 12 weeks old. I am feeding the plant general hydroponics flora series, and following there schedul. About 750ppm rite now. The soil is coco mixed with perlite and earthworm castings
 

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JohnDee

JohnDee

Well-Known Member
RussianReaper said:
The soil is coco mixed with perlite and earthworm castings
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RR,
Coco is not soil and should not be treated as such. Are you feeding nutes with every watering. Do you ph your waterings...to what ph. Are you watering to 20% runoff.

Tell us what you are actually doing so we know how you got there. I'm pretty sure you have a Mg thing going on. Giving any calmag?
JD
 
RussianReaper

RussianReaper

Member
I am feeding nutes every watering. Usually have ph about the 6.0 mark. I do give about 20% run off. FOr every gallon of nute mix I add 1.5 to 2ml of calmag.
 
jarvild

jarvild

Well-Known Member
You'll want a minimum of 6% cal in your feed make-up and around 2.5% as a minimum for mag.
I'm not a big fan of cali-magic as it uses calcium carbonate as it's cal source which is not readily available immediately as the bonds between the cal and carbonate has to be broken down before it's available to the plants
 
hotrodharley

hotrodharley

Well-Known Member
jarvild said:
You'll want a minimum of 6% cal in your feed make-up and around 2.5% as a minimum for mag.
I'm not a big fan of cali-magic as it uses calcium carbonate as it's cal source which is not readily available immediately as the bonds between the cal and carbonate has to be broken down before it's available to the plants
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Wrong. Calcium carbonate is exactly what's in limestone and dolomite lime we commonly add to soil. Gypsum is also used but is calciujm sulfate. The bond is ionic only and either the carbon or the sulfur is also utilized.
 
jarvild

jarvild

Well-Known Member
hotrodharley said:
Wrong. Calcium carbonate is exactly what's in limestone and dolomite lime we commonly add to soil. Gypsum is also used but is calciujm sulfate. The bond is ionic only and either the carbon or the sulfur is also utilized.
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We'll just have to disagree on this one.
First the guys in coir. Second take a handful of dolomite and throw it in a bucket of water and a handful of gypsum in another bucket, see whats left in the bottom of the buckets if you think carbonate bonds are that easy to get rid of. Third is it's well known in the agri-industry that dolomite is a slow release cal source and gypsum is a fast release cal source.
 
hotrodharley

hotrodharley

Well-Known Member
jarvild said:
We'll just have to disagree on this one.
First the guys in coir. Second take a handful of dolomite and throw it in a bucket of water and a handful of gypsum in another bucket, see whats left in the bottom of the buckets if you think carbonate bonds are that easy to get rid of. Third is it's well known in the agri-industry that dolomite is a slow release cal source and gypsum is a fast release cal source.
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Nobody is talking speed of release. So tell us which form of calcium is the proper one to use
 
polishpollack

polishpollack

Well-Known Member
We now return to our regular programming:
The grower is over fertilizing. 750ppm is more of a true hydro level, meaning that you grow with this level in nothing but water. Coco fibers will trap nutrients and hold them for a while. The plants are showing classic over fert signs, the leaf tips yellowing/browning and the edges starting to do the same. Good chance you don't need to fert every watering too. I'd say try 300ppm for a while and do so with every other watering as see how that works. I can only guess on the dosage unfortunately as I don't use coco. But I know that those fibers will trap water and nutrients for a time. This actually looks like a very good attempt at a coco grow but you've over done it on the ferts. In coco, I bet you have to use nutrients that are a ready-to-use type, so I wouldn't worry about the above discussion on calcium. Use a fert that has calcium and magnesium in it already and you'll be fine on those. As the plants get bigger, you should bump up the nute level some unless it looks like their still doing so good that you have it perfected, then just go with that.
 
RussianReaper

RussianReaper

Member
polishpollack said:
We now return to our regular programming:
The grower is over fertilizing. 750ppm is more of a true hydro level, meaning that you grow with this level in nothing but water. Coco fibers will trap nutrients and hold them for a while. The plants are showing classic over fert signs, the leaf tips yellowing/browning and the edges starting to do the same. Good chance you don't need to fert every watering too. I'd say try 300ppm for a while and do so with every other watering as see how that works. I can only guess on the dosage unfortunately as I don't use coco. But I know that those fibers will trap water and nutrients for a time. This actually looks like a very good attempt at a coco grow but you've over done it on the ferts. In coco, I bet you have to use nutrients that are a ready-to-use type, so I wouldn't worry about the above discussion on calcium. Use a fert that has calcium and magnesium in it already and you'll be fine on those. As the plants get bigger, you should bump up the nute level some unless it looks like their still doing so good that you have it perfected, then just go with that.
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Thanks a bunch, maybe I will do a flush and like you said bring my ppm down to 300 to 350 and see what that does. I never really looked at over fert being the issue, I have 3 more plants in there all are diff strains 1 witch is an autoflower and they are all taking the same ferts. Maybe this hashplant strain don’t like much ppm. Thanks a bunch
 
jarvild

jarvild

Well-Known Member
polishpollack said:
We now return to our regular programming:
The grower is over fertilizing. 750ppm is more of a true hydro level, meaning that you grow with this level in nothing but water. Coco fibers will trap nutrients and hold them for a while. The plants are showing classic over fert signs, the leaf tips yellowing/browning and the edges starting to do the same. Good chance you don't need to fert every watering too. I'd say try 300ppm for a while and do so with every other watering as see how that works. I can only guess on the dosage unfortunately as I don't use coco. But I know that those fibers will trap water and nutrients for a time. This actually looks like a very good attempt at a coco grow but you've over done it on the ferts. In coco, I bet you have to use nutrients that are a ready-to-use type, so I wouldn't worry about the above discussion on calcium. Use a fert that has calcium and magnesium in it already and you'll be fine on those. As the plants get bigger, you should bump up the nute level some unless it looks like their still doing so good that you have it perfected, then just go with that.
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As I've been growing in coir for 10 years and using LEDs. I see classic signs of cal-mag imbalance in his plants. Whether his plants are over fed is subjective because with the imbalance of cal-mag it throws the uptake of other nutrients out of balance also.
Coir has a natural pH of 6.2-6.4 perfect for growing our plants. So why would you add calcium in the carbonate form that will raise the pH over time. Sure you add it in peat based soils as the natural pH of peat is 4.9 pH so you need the buffering ability of the carbonates.
I'm not saying that the addition of calcium carbonates doesn't supply some cal that's usable by the plants it's just he doesn't need the buffering in his medium from it in the form of the carbonates.
 
Thegermling

Thegermling

Well-Known Member
polishpollack said:
We now return to our regular programming:
The grower is over fertilizing. 750ppm is more of a true hydro level, meaning that you grow with this level in nothing but water. Coco fibers will trap nutrients and hold them for a while. The plants are showing classic over fert signs, the leaf tips yellowing/browning and the edges starting to do the same. Good chance you don't need to fert every watering too. I'd say try 300ppm for a while and do so with every other watering as see how that works. I can only guess on the dosage unfortunately as I don't use coco. But I know that those fibers will trap water and nutrients for a time. This actually looks like a very good attempt at a coco grow but you've over done it on the ferts. In coco, I bet you have to use nutrients that are a ready-to-use type, so I wouldn't worry about the above discussion on calcium. Use a fert that has calcium and magnesium in it already and you'll be fine on those. As the plants get bigger, you should bump up the nute level some unless it looks like their still doing so good that you have it perfected, then just go with that.
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First of all if youve dont use coco why are you giving advice? Honestly, I know people want to help but if you dont have experience in coco why even bother.
To the OP you have a magnesium deficiency. I agree with jarvild. Your nutrient ratios must not be balanced and thats why you are seeing this deficiency.
Also, dont go by that feeding chart. I dont think GH made those nutrients for coco. Also something like heads formula for coco using GH is more in your alley.
What I would do, in your situation, well Ive never used GH before so I dont really know what to tell you:cry:. Maybe someone who uses GH in coco can help.
EDIT: Dont add magnesium because you can lock out other elements or cause an increase in other elements (antagonism and synergism). Id flush with 0.9 EC and try to look around for advice on the best GH ratios. I suggest Heads formula.
 
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RussianReaper

RussianReaper

Member
Thegermling said:
First of all if youve dont use coco why are you giving advice? Honestly, I know people want to help but if you dont have experience in coco why even bother.
To the OP you have a magnesium deficiency. I agree with jarvild. Your nutrient ratios must not be balanced and thats why you are seeing this deficiency.
Also, dont go by that feeding chart. I dont think GH made those nutrients for coco. Also something like heads formula for coco using GH is more in your alley.
What I would do, in your situation, well Ive never used GH before so I dont really know what to tell you:cry:. Maybe someone who uses GH in coco can help.
EDIT: Dont add magnesium because you can lock out other elements or cause an increase in other elements (antagonism and synergism). Id flush with 0.9 EC and try to look around for advice on the best GH ratios. I suggest Heads formula.
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Never heard of heads formula will look into it tomorrow. Thanks a bunch. Is there a good grow chart to follow for the heads formula?
 
Thegermling

Thegermling

Well-Known Member
RussianReaper said:
Never heard of heads formula will look into it tomorrow. Thanks a bunch. Is there a good grow chart to follow for the heads formula?
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Copy and paste from Internation Cannagraphic, click on growing in coco coir, and click on "H3ad goes Coco" for more info.
"In the coco, I am now using 6ml/gal micro and 9ml/gal bloom which gives the nute profile:
N 97
P 60
K 105
Mg 41
S 27
Ca 97

adding 1 g/gal epsom salts to the solution changes the numbers for mg and s to:
Mg 67
S 61


Adjusting for the extra available potassium in the coco, the new formula puts me very close to the 'target ratio'... Phosphorous is a tad low, but I think there should be no worries there...

Nothing is too far along in flower right now, but I'll get some pics up a bit later.

I have also seen advantage in keeping the coco fairly wet, I'm guessing that the coco holds the nutes so well, that as moisture evaporates out, concentrations rise..."
I hope you dont have hard water but I remember somewhere in the thread he figures out the ratios for that. He drops epsom salts later in the thread but I dont remember much so youll have to read for more info. Cheers!
 
polishpollack

polishpollack

Well-Known Member
I responded because the leaves look like over ferting. germling says it's a magnesium deficiency, then makes an edit and adds in "don't give magnesium." Hmm. Also, a flush with 0.9 ec isn't a flush. Only use water to flush.
 
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