Coco specific nutrients, Potassium amount

[Coconaut81]

Hello friends! I've embarked on the raw salt journey a little while ago, and loving avoiding the hydro store. I started with jacks, then masterblend. Now I tweak the masterblend with salts in veg. I've read so much, and taken so many notes, my head hurts. And still more to learn! Many of you have helped me so much, much love to you all!!

I know I've read this somewhere, but can't find it again.. does anybody know how much Potassium coco naturally adds to a nutrient mix? I'm trying to figure where to adjust my Potassium to for a veg formula. I'm thinking 150-160ppm to match the nitrogen.. In flower, I just run masterblend full strength after stretch. Ive been treating that 205ppm of Potassium as a bloom booster. Masterblend alone is great at finishing them. I'm under Samsung 301b chips

 

[Cerathule]

Once the coco has been washed and buffered then the Ca or Mg ions will have replaced the K from the CEC and the K alongside the NaCl will be gone.
But it also depends on the buffer, Calnit is far more effective than Epsom. There was a consumer test years back on cocopeat and result showed a remnant of merely 9mg/l K when using Calnit, while still 230mg/l under Epsom. Unwashed K levels tested high up to 1566mg/l and washed with water brought that down already to 355mg/l K.

 

[Coconaut81]

Once the coco has been washed and buffered then the Ca or Mg ions will have replaced the K from the CEC and the K alongside the NaCl will be gone.
But it also depends on the buffer, Calnit is far more effective than Epsom. There was a consumer test years back on cocopeat and result showed a remnant of merely 9mg/l K when using Calnit, while still 230mg/l under Epsom. Unwashed K levels tested high up to 1566mg/l and washed with water brought that down already to 355mg/l K.

I was under the impression coco gave off more and more potassium as it decomposes.

If the Ca and Mg ions replace the K and NaCl, it wouldn't make sense that nutrient manufacturers use less potassium in their formulas with all the R&D.

 

[SuperBadGrower]

According to the manicbotanix website, Canna's test says the coco releases 37 ppm K

RE: target ppm;

Effect of Potassium (K) Supply on Cannabinoids, Terpenoids and Plant Function in Medical Cannabis

We have demonstrated in previous studies that the essential macro-nutrients nitrogen (N) and phosporous (P) have profound effects on the production of cannabinoids and terpenoids in the cannabis plant. The present study was undertaken to evaluate the hypothesis that potassium (K) supply, which...

www.mdpi.com

 

[SuperBadGrower]

https://www.researchgate.net/publication/354093519_Optimization_of_N_P_K_for_Soilless_Production_of_Cannabis_sativa_in_the_Flowering_Stage_Using_Response_Surface_Analysis

There another one

 

[Dr.RedWhite]

Outstanding link!

 

[goingrey]

According to the manicbotanix website, Canna's test says the coco releases 37 ppm K

RE: target ppm;

Effect of Potassium (K) Supply on Cannabinoids, Terpenoids and Plant Function in Medical Cannabis

We have demonstrated in previous studies that the essential macro-nutrients nitrogen (N) and phosporous (P) have profound effects on the production of cannabinoids and terpenoids in the cannabis plant. The present study was undertaken to evaluate the hypothesis that potassium (K) supply, which...

www.mdpi.com

Very interesting! (Relatively) High levels of K are needed during veg already. And for quality feed low in N, P and K (not just N). For yield feed high.

​

at the vegetative growth phase, low K levels of 15 mg L−1 (ppm) caused growth retardation and visual deficiency symptoms in two medical cannabis cultivars, induced by impaired water relations, transpiration, and carbon fixation [16]. The response to K supply at the vegetative growth phase varied slightly between the two cultivars [16]. Despite the significant competition for root uptake between K, Ca and Mg, the results suggested that a supply of 175–240 mg L−1 K is optimal for medical cannabis production at the vegetative growth ​

...​

the concentrations of the acidic forms of the cannabinoids in the inflorescences, i.e., THCA, CBDA, CBGA, CBCA, THCVA, and CBDVA, were all highest under the low K treatment of 15 mg L−1 K, and generally declined with further increase sin K supply ​

...​

In general, growth, biomass accumulation, and yield production were lowest under the low K treatment of 15 mg L−1 K, and were not substantially influenced at the range of 60–240 mg L−1 K​

...​

At the reproductive phase of growth, low inputs of N and P promoted cannabinoid and terpenoid production, and increasing N and P supply generally decreased the plant’s secondary metabolism.​

The other paper was also interesting.

Yo @George you might be interested in these as well.

 

[SuperBadGrower]

Cheers, yes they are good reading. enjoy.

I was wrong about "continuous release", the 37 ppm K is just a test of canna coco in USA from 2011
source:

Site permanently closed due to piracy and trading off Issues

Site permanently closed due to piracy and trading off Issues. Manic Botanix, nor its author, is in no way linked to any commercial interests claiming a link. Full stop. Contact [email protected] or follow on Instagram @manicbotanix

manicbotanix.com

 

[George]

Very interesting! (Relatively) High levels of K are needed during veg already. And for quality feed low in N, P and K (not just N). For yield feed high.

​

at the vegetative growth phase, low K levels of 15 mg L−1 (ppm) caused growth retardation and visual deficiency symptoms in two medical cannabis cultivars, induced by impaired water relations, transpiration, and carbon fixation [16]. The response to K supply at the vegetative growth phase varied slightly between the two cultivars [16]. Despite the significant competition for root uptake between K, Ca and Mg, the results suggested that a supply of 175–240 mg L−1 K is optimal for medical cannabis production at the vegetative growth ​

...​

the concentrations of the acidic forms of the cannabinoids in the inflorescences, i.e., THCA, CBDA, CBGA, CBCA, THCVA, and CBDVA, were all highest under the low K treatment of 15 mg L−1 K, and generally declined with further increase sin K supply ​

...​

In general, growth, biomass accumulation, and yield production were lowest under the low K treatment of 15 mg L−1 K, and were not substantially influenced at the range of 60–240 mg L−1 K​

...​

At the reproductive phase of growth, low inputs of N and P promoted cannabinoid and terpenoid production, and increasing N and P supply generally decreased the plant’s secondary metabolism.​

The other paper was also interesting.

Yo @George you might be interested in these as well.

We got a lot of great articles here very cool. I find it interesting they say 175 provided optimal growth and function but then recommend 60ppm in the abstract.

Personally this is the most damning pic showing K input and K runoff. 100ppm seems about the max before we start to get unused K at least on these cultivars in veg. They simply don't seem to want more. Check out the steep rise in K build up. imagine this happening when your plants need lots of calcium right after you flip and go into transition, after you've been vegging in a 270ppm K mix for 2-4 weeks. They have build up by day 7 with 175K vs the 100k. The article you post shows a very cool interaction between K input and Ca/Mg availability.

Edit: this is not in coco though. So not quite what were looking for but I think we can assume if 100 K is enough to function in perlite then surely its enough in coco.

 

[goingrey]

Hmm yeah. The DQ strain showed a considerable increase in flower yield with 175 mg/l. And the runoff doesn't seem to spike as much either, especially when looking at the full 60 days. The RM strain did not get an increased yield and the runoff spiked earlier (faster flowering strain it seems so the timespan is different).

Total THC reduction going from 60 mg/l to 175 mg/l was a couple percentage points for both it seems. For the higher THC DQ strain this is not so drastic and running at 175 mg/l provides a much higher yield of THC (about 25% more). For the lower THC RM strain, that did not even gain an increase in flower yield, this reduction is quite drastic and running the higher concentration makes no sense at all.

Had I written the abstract I would have said the correct concentration is highly strain dependent. Lesson learned, always read the entire paper and supplemental material, not just the abstract.

 

[Ca++]

With K dropped from an otherwise balanced food, plants were fertigated 3 times a day for 3 days. Giving 30% runoff. This was done just past the peak of flower formation. When excess K has been shown to increase yield in other species. Leading to the high K levels we sometimes use.
At the end of day 3, the runoff of the third fertigation that day, having provided the plants with all their K needs, measured ~100ppm K.

That was canna on it's first run. Other tests showed no significant change with older coco. However, decomposition speed increases with the coco's age and canna coco coir kept sopping wet is going to be breaking down pretty quick anyway. It's already coco peat, not fiber.

Canna feeds for most substrates are about 160ppm K but their coco feed is more like 60.


Some studies are leading to recommendations around 180ppm K, while others are saying K does next to nothing. It seems to be a coin toss, with no clear winner, though the results are in one of the two camps.

I don't like K. Never have. PK boosters have only ever made my plants ill, and the same goes for the people around me. I feel 180ppm might be needed, or won't hurt. Beyond that it's really about dialing in the specific plant. Which as a mixed batch grower, I have never done.

 

[Cerathule]

Is there any data out there how swiftly cocopeat breaks down (=to what?) in a mineralic/sterile (H2O2 or Chloride) setup? There are reports people reuse it for +2 years.

So many studies with cannabis show how broad the range of the genetics are...

 

[Ca++]

'reusing' is itself a bit vague. It's never going to be just coco, once it's had roots through it. Over time, the substrate becomes a compost to look at it.
For some time, my finals were recycled coco, but the veg stage was fresh. This meant perhaps a 15% renewal in the finals. This went on indefinitely. It perhaps takes that two years to really get into the stride of things. Where what you have, in no way, resembles coco. It's a compost, due to the huge volume of roots in it. No effort was made to speed up their decay and at one time a 'no till' method ran for a couple of years. Just coring out the final for the veg plant to sit in the hole. This might be different where enzymes are used.

We might have to look at them coco making pits to really get an idea. I think they rot the husks for about 2 years. Quite a bit happens in that time, without things that would accelerate the process. I know there are documentaries on this, but I have not watched one. I think there is then grading. Taking the peat from the husk, to look at just two aspects of coco grading. I don't really know.
Canna talk about reuse. I think a few times. It's there they talk of decomposition speed increasing. Something I have not really seen, as the roots in there seem to make the real difference.

The rate things rot isn't fixed enough to really put numbers on it. Too many things influence it. Heat, bacterial presence, chemical attack, pH, ionic influences, how wet.. I bet there are others. I think a lot happens in a couple of years though.

Incidentally, it's always been better to sieve through the coco, than no-till. They get a better start. Later, it's compact again anyway.

 

[George]

Hmm yeah. The DQ strain showed a considerable increase in flower yield with 175 mg/l. And the runoff doesn't seem to spike as much either, especially when looking at the full 60 days. The RM strain did not get an increased yield and the runoff spiked earlier (faster flowering strain it seems so the timespan is different).

Total THC reduction going from 60 mg/l to 175 mg/l was a couple percentage points for both it seems. For the higher THC DQ strain this is not so drastic and running at 175 mg/l provides a much higher yield of THC (about 25% more). For the lower THC RM strain, that did not even gain an increase in flower yield, this reduction is quite drastic and running the higher concentration makes no sense at all.

Had I written the abstract I would have said the correct concentration is highly strain dependent. Lesson learned, always read the entire paper and supplemental material, not just the abstract.

Its pretty cool imo and kind of helps explain why some growera are adamant their P and/or K additions are helping (because their varieties want it) and others say their plants got worse (obv those didn't want it). The plants variability has caused a lot of arguments over the years for people that were both technically correct lmao