NPK changes from Calmag

MisterBlah

Well-Known Member
I grow in peat and not only do I recommend my feeding style there are 100's of growers using it and also not having any Mag def's a few of em are soil growers, a few are hydro growers a few use coco and why do we do this ? because it makes for more potent buds
As I said, concentration is important. So, how much of each of those are you using?
 
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RM3

Well-Known Member
It seems as though JRPeters has stopped producing that blend. I can't find a label for it anywhere and it's no longer listed on their website.
They designed it for cannabis and only promote it to legal states you have to contact them and ask for it, it has never been on the website
 

MisterBlah

Well-Known Member
Well, short of getting the rest of the info on the label, here's where you stand on concentration.

1/4-1/2 teaspoon. 1 tsp is about 5ml, 1/4 is 1.25ml, so lets call it 1.7ml of the product. Loosely packed density is going to be about 1.25g/ml.
1.25g/ml*1.7ml = 2.12g.
2.12g/gal = 0.56g/l

1/8 tsp = 0.78g/gal = 0.2g/l

AquaGold Finisher
7% N, 15% P2O5, 30% K2O @ 0.56g/l
Sulfate of Potash
50% K2O, 15% S @ 0.56g/l
Epsom Salt
10% Mg, 13% S @ 0.2g/l

From Aqua Gold Finisher:
39.2 ppm total N
84 ppm P2O5 (36.6 ppm total P)
168ppm K2O (139.4 ppm total K)

From Sulfate of Potash:
280 ppm K2O (232.4 ppm total K)
84 ppm S

From Epsom Salt:
20 ppm Mg
26 ppm S

Totals:
39.2 ppm Total N
36.6 ppm Total P
371.8 ppm Total K
20 ppm Mg
110 ppm S

The reason why you aren't seeing any problems is because you are at low enough concentrations.

Now, for some comments on your concentrations:
N - low. Recommended around 100-120 ppm during flower
P - low. Recommended around 50-90 ppm during flower
K - high. Recommended around 200-300. However, being this high isn't a huge problem, as you've clearly seen. I've seen 450+ Total K in fertilizer programs in some types of hydroponics and it not being an issue.
Ca - No data, so the best I can do is assume 0-20, If you provide a water sample, I'd can give you some insight on this.
Mg - Low, but also, limited data. With a water sample, I'd know for sure what it really is.
S - Moderate. No need to modify this much. Changing is +/- 40ppm is fine and you won't notice a difference.

If I were you, I would increase your phosphorus, nitrogen, and calcium levels.

I would do the following:

Reduce SOP 0-0-50 to 1/8 tsp.
Add 1/4 tsp of Calcium Nitrate
Add 1/8 tsp of MKP, MonoPotassium Phosphate

This will do the following:
Add 64 ppm Total N
Add 45 ppm Total P
Reduce Total K by 37.2 ppm.
Add 81 ppm Ca
 

SSHZ

Well-Known Member
What ferts are people using thats that low in calcium that you need more?

All mine are quite high in calcium, almost as high as nitrogen and potassium....
This is always an issue if you use a reverse osmosis device, as it removes most everything from the water. General water out of the tap will have some ppm (calcium and maybe some mg) in it, but not after you run it thru the machine. I have to add 10ml of my cal/mag additive with EVERY gallon of water I feed with or my plants start to show some leaf tacoing, or another words the deficiency.

I stop adding cal/mag about 2 weeks out from chopping.........and I also add 3.75 cups of dolomite lime to my 4 gallon pots in the mixing stage (it has a lot of calcium in it) but I think it takes a long time to break down properly.
 

RM3

Well-Known Member
Well, short of getting the rest of the info on the label, here's where you stand on concentration.

1/4-1/2 teaspoon. 1 tsp is about 5ml, 1/4 is 1.25ml, so lets call it 1.7ml of the product. Loosely packed density is going to be about 1.25g/ml.
1.25g/ml*1.7ml = 2.12g.
2.12g/gal = 0.56g/l

1/8 tsp = 0.78g/gal = 0.2g/l

AquaGold Finisher
7% N, 15% P2O5, 30% K2O @ 0.56g/l
Sulfate of Potash
50% K2O, 15% S @ 0.56g/l
Epsom Salt
10% Mg, 13% S @ 0.2g/l

From Aqua Gold Finisher:
39.2 ppm total N
84 ppm P2O5 (36.6 ppm total P)
168ppm K2O (139.4 ppm total K)

From Sulfate of Potash:
280 ppm K2O (232.4 ppm total K)
84 ppm S

From Epsom Salt:
20 ppm Mg
26 ppm S

Totals:
39.2 ppm Total N
36.6 ppm Total P
371.8 ppm Total K
20 ppm Mg
110 ppm S

The reason why you aren't seeing any problems is because you are at low enough concentrations.

Now, for some comments on your concentrations:
N - low. Recommended around 100-120 ppm during flower
P - low. Recommended around 50-90 ppm during flower
K - high. Recommended around 200-300. However, being this high isn't a huge problem, as you've clearly seen. I've seen 450+ Total K in fertilizer programs in some types of hydroponics and it not being an issue.
Ca - No data, so the best I can do is assume 0-20, If you provide a water sample, I'd can give you some insight on this.
Mg - Low, but also, limited data. With a water sample, I'd know for sure what it really is.
S - Moderate. No need to modify this much. Changing is +/- 40ppm is fine and you won't notice a difference.

If I were you, I would increase your phosphorus, nitrogen, and calcium levels.

I would do the following:

Reduce SOP 0-0-50 to 1/8 tsp.
Add 1/4 tsp of Calcium Nitrate
Add 1/8 tsp of MKP, MonoPotassium Phosphate

This will do the following:
Add 64 ppm Total N
Add 45 ppm Total P
Reduce Total K by 37.2 ppm.
Add 81 ppm Ca
Well now I know who to ask if I need nute math breakdowns, you obviously know it, it seems.

That said, I am not a noob looking for help, I have been growin for 44 years and have written 2 books on the subject as well as post and threads here at RIU with over a million total views. There are a lot of folks that would tell you I have forgotten more about this plant than most growers know.

The low N is key to higher potency, High P is not ever needed if growing in containers (out side is different as is hydro) I live in Denver, our water is is on the top 10 best list in the US, has plenty of Cal and yes I simply and mostly use tap water feeding only enough to keep the plants healthy & green it's a long lost art that I am trying to bring back

Most MJ growers are truly clueless as they follow myths and nonsense spread on these forums, the less is more mantra is very real
 

RM3

Well-Known Member
Does this plant look like it needs N?

Do you see any nute deficiencies?

At 6.5 weeks does it appear to be maturing properly?
.
T_SAM_3774.JPG
 

MisterBlah

Well-Known Member
Well now I know who to ask if I need nute math breakdowns, you obviously know it, it seems.

That said, I am not a noob looking for help, I have been growin for 44 years and have written 2 books on the subject as well as post and threads here at RIU with over a million total views. There are a lot of folks that would tell you I have forgotten more about this plant than most growers know.

The low N is key to higher potency, High P is not ever needed if growing in containers (out side is different as is hydro) I live in Denver, our water is is on the top 10 best list in the US, has plenty of Cal and yes I simply and mostly use tap water feeding only enough to keep the plants healthy & green it's a long lost art that I am trying to bring back

Most MJ growers are truly clueless as they follow myths and nonsense spread on these forums, the less is more mantra is very real
A lot of the data that I use comes from cut flower plants. Seeing as cannabis is a normal cut flower plant, it mostly applies all the same.

If you're in Denver, you've probably got 4 ppm Total K, 17ppm of Ca, 4ppm Mg, 16 ppm S. I have a water test from Denver water on my desk. :)

And yes, you're right that growing in different media means you're going to have different fertilizer blends. A lot of the numbers I listed about are more appropriate for hydroponics. And when it comes to soil, peat, etc. in containers or soil outdoors, everything changes depending on what is in the media.

As for what higher or lower concentrations of any specific nutrient do, I won't argue that. There just isn't enough data to support either side of any argument.
 

RM3

Well-Known Member
As for what higher or lower concentrations of any specific nutrient do, I won't argue that. There just isn't enough data to support either side of any argument.
Plenty of data, but ya gotta look at hemp, not cannabis. Are you aware that hemp growers feed high N to reduce THC in their plants and maintain the hemp standard set forth by our guberment
 

RM3

Well-Known Member
It looks like a fine healthy plant to me.

Out of curiosity, have you ever gotten a lab test done on your growing media?
No. as I have no need, I follow no schedules, everything I do is based on plant response. After watchin em for as long as I have I've gotten pretty good at it

My lowest tested strain was 21% THC
 
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