Is the K too low?

Wasn't able to get any help on this in the nutrient section. Has anybody ran a ppm in this kind of lower K/c/s range?, is it possible kelp foliar until flower set would fill in the gaps?.


Base + 0.5gpl Cnitrate + 1/4gpl epsom salt (veg+pre-flower)

N = 139ppm
P = 63ppm
K = 90ppm

C - 95
M- 55
S - 32
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Base + 1/4 gpl Cnitrate + 1/4gpl epsom salt + 0.10gpL MKP (from flower set to taper down)

N - 99ppm
P - 85ppm
K - 120 (is this too low?)

C - 47ppm (is this too low from week 4 onward?)
M -55ppm
S - 32ppm (also potentially low?)

I don't think it is terribly low. I think a 3:1:2 ration is a general rule of thumb.

I think for flowering the K is low. For flowering I use a 1:1:2 ratio. Maybe add some potassium sulfate.

70's natureboy said:

I don't think it is terribly low. I think a 3:1:2 ration is a general rule of thumb.

Click to expand...

Merlin1147 said:

I think for flowering the K is low. For flowering I use a 1:1:2 ratio. Maybe add some potassium sulfate.

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Yeah I just remember a lot of hype about high K toward the end increasing potency (maybe they got that slightly wrong and it was indirectly the S in a Psulfate?). I'm not so sure how K plays with coco, I recall that it will start to release K after a certain time. I am currently using a 2-1-4 as a base from start to finish but I think perhaps the K is building too much by week 5/6. With something closer to a 3-1-2 for veg then ''kind of'' a 1-1-2 for late flower this would all be solved. There is no toxicity to speak of with the current 2-1-4 but leaves darkening like that just doesn't seem right. I figured it was N and payed more attention to the transition levels, but I don't think it's that. It could be K build up or maybe even magnesium build up?. I've read also mag can darken leaves.

Merlin, if I am correct that coco holds onto K but releases it later, would the 3-1-2 kind of ratio off set the build up or would you expect to see a K deficiency in early/mid flower?. None the less I think you are right that the addition of K sulf seems required. Do you think I could stop using mkp and do ok with P levels at around 60?. If not I will ofc have to use it too.

If this does turn out to actually just be higher N levels then can anybody give me advice on how to lower Cnitrate and not reduce calcium? I don't know how much calcium mj needs past week 4, nobody seems to know this either. I just worry about low C since a lot of veg growers say it is the reason for end crop rot.. and I assume this will also pass over to MJ.

I broke down what is in what I use but I can't seem to find the file with the numbers.

Basically I use 1/2 tsp / 3 grams calcium nitrate per gallon and 1/2 tsp of a micronutrient blend similar to Jacks 4-10-20 for veg. I keep the same formula in flower but add 1/4 tsp / 1.5 grams MKP per gallon. I run that formula until about week 5 of flower when I add 1/4 tsp of potassium sulphate for a couple weeks then cut out the potassium sulphate and start to taper down the nutrients to where I'm using around 1/4 strength at the end.

I don't know if that helped any. It's too early to break it down to ppm numbers and I have that somewhere just need to find that file somewhere on my computer.

Have you thought about cutting back the calcium nitrate and using another form of calcium to replace the calcium you reduce by using less calcium nitrate?

Something like this perhaps?

"Calcium is chelated by EDTA, for use in agriculture and in horticulture as foliar feed (secondary nutrient). Also ideal for use in fertigation, hydroponics and soil application systems.

Guaranteed Analysis:

Calcium (Ca) water soluble, chelated by EDTA............9.7%

Use this product to supplement the calcium in your nutrient solution that is supplied by calcium nitrate. One gram of Dissolvine E-Ca-10 per gallon final volume nutrient solution provides approximately 25ppm calcium."

http://customhydronutrients.com/yara-rexolin-caedta-chelated-cal-c-1_47_452/calcium-edta-chelated-97-one-pound-p-763.html

xtsho said:

I broke down what is in what I use but I can't seem to find the file with the numbers.

Basically I use 1/2 tsp / 3 grams calcium nitrate per gallon and 1/2 tsp of a micronutrient blend similar to Jacks 4-10-20 for veg. I keep the same formula in flower but add 1/4 tsp / 1.5 grams MKP per gallon. I run that formula until about week 5 of flower when I add 1/4 tsp of potassium sulphate for a couple weeks then cut out the potassium sulphate and start to taper down the nutrients to where I'm using around 1/4 strength at the end.

I don't know if that helped any. It's too early to break it down to ppm numbers and I have that somewhere just need to find that file somewhere on my computer.

Click to expand...

If you could find those notes it would be helpful, I too am not in the mood for that right now ;p. I will work out what you use in a day or two if you can't find them by then, no worrys either way thnx. I assume American gallon though yes?.

xtsho said:

Have you thought about cutting back the calcium nitrate and using another form of calcium to replace the calcium you reduce by using less calcium nitrate?

Something like this perhaps?

"Calcium is chelated by EDTA, for use in agriculture and in horticulture as foliar feed (secondary nutrient). Also ideal for use in fertigation, hydroponics and soil application systems.

Guaranteed Analysis:

Calcium (Ca) water soluble, chelated by EDTA............9.7%

Use this product to supplement the calcium in your nutrient solution that is supplied by calcium nitrate. One gram of Dissolvine E-Ca-10 per gallon final volume nutrient solution provides approximately 25ppm calcium."

http://customhydronutrients.com/yara-rexolin-caedta-chelated-cal-c-1_47_452/calcium-edta-chelated-97-one-pound-p-763.html

Click to expand...

Yeah you might well be right about the calcium product, I neglected learning what types of single source calcium were good, since there was some mixed opinions. It might be time to give it a go. Do you know how much calcium is required for mid/late flower?, it's also part of what was putting me off using it.

Anyway, thnx for the help.