[spurr]

Chlorine dioxide:

• Stops algae growth in reservoir and on media
• Prevents drip emitter clogging from microbial biofilm
• Prevents root pathogens and reduces nitrification of NH4 into NO3
• Etc.

I plan to use chlorine dioxide at 0.25 ppm (residual) in nutrient solution, which has been found to not hinder root or plant growth, but offers sufficient efficacy to accomplish the above noted benefits.

Using choline dioxide should work much better than hydrogen peroxide, and it's easier to use and lasts a lot longer too. You buy a packet from SelectMicro, called "Selectrocide", and you mix it with distilled water to make a 500 ppm stock solution. Then you dilute it to whatever ppm you want. For constant use 0.25-0.5 ppm is recommend by Greenhouse Grower Magazine, in this good article "Chlorine Dioxide In Horticulture: A Technology Review" (P.Konjoian, 2011). P. Konjoian also covers use of higher ppm chlorine dioxide to kill root pathogens already going strong, like root rot.

It used to require a choline dioxide generator, on-site, to use chlorine dioxide for plants. Which is why I think it never caught on for cannabis growers. I have never read a single grower ever write about it, before myself (that's not to say no one has, I could be ignorant). Now, thanks to SelectMicro we can have ultra pure choline dioxide stock solution for low cost per packet. Sadly, the only retail sources at this time sell in bundles of a 5 or 10 or more packets, so it's at least ~$150 to get going with chlorine dioxide ... unless the owner of Custom Hydro Nutrients would carry it and sell them by single packs ... hint, hint to CHN

Here's what I'm testing this next grow at 0.25 ppm, I should have it in by next week some time:

https://www.selectivemicro.com/produc...ocide2l500.php

The Selectrocide® 2L500 generates 2 liters of 500 ppm ultra pure Chlorine Dioxide. It is offered in a self contained pouch. Simply remove the cap and add water. Replace the cap and let the product generate for 6 hours. Dilute the solution to fit your needs. The 2L500 is registered with the Environmental Protection Agency as a pesticide and falls within the categories of lowest toxicity. We recommend the 2L500 for agricultural products, hard-nonporous surfaces and general sanitization.

Originally Posted by spurr

On what? The plant or the water or something else, like ions?

I mean will using sugars, fulvic, enymes and other plant extracts in my dtw res defeated the purpose of preping the water as u suggest

Also useing your method to prep the water making some sort of chemical reaction or what major benefits vs most people adding nutes then using ph up or down.

Currently I am using RO putting protek in 1st then floranova grow then calmag then sweet

next question is the orthosilicic acid in addition to protek or ahsil 16h?

great stuff as usual spurr ....... glad you decided to smoke weed instead of work for the government.

For those who wanna try flower mode with spurs recipe but not deal with all the bulk salts.

Mix flower water per intructions use his old 5/5/5/5 minus protek add .42gram DAP its round 10ppmK less

11mins 5secs into video is cheat sheet for his educated guesses

only thing I need to get is some DAP and Agsil16

[iSMOKE.KUSH]

Originally Posted by DonkDBZ

For those who wanna try flower mode with spurs recipe but not deal with all the bulk salts.

Mix flower water per intructions use his old 5/5/5/5 minus protek add .42gram DAP its round 10ppmK less

11mins 5secs into video is cheat sheet for his educated guesses

only thing I need to get is some DAP and Agsil16

you mean the 5/5/7/5? hehe.

.42 grams of DAP per gallon? also whats the best price anyone has seen on DAP?

are you still using the silicon in veg?

p.s. just about to harvest my first full round using spurrs current profile (5/5/7/5/2.5/.5g), and it is looking stellar. 16 lights of some of the nicest looking flowers i've grown to date. mucho excited..

[dizzlekush]

Originally Posted by spurr

Yup. I am going to use 80 ppm Si in veg, which is 2.848 milliMolar/L Si and 273.6 ppm "orthosilicic acid" (H4SiO4; the plant usable form of silicon). I am going to use 90 ppm Si in early-flowering (and nearly that in full-flowering), which is 3.204 mmol/L Si and 307.8 ppm orthosilicic acid, aka "monosilicic acid" aka "silicic acid". A commonly used concentration of Si in nutrient solutions is 100 ppm, some people claim it's 100 ppm SiO2, but that's incorrect. It's a claim made from an aged report on silicon and plants.

For hydroponic research it has been found upwards of 5 to 10 mM Si can be beneficial, esp for PM and heat issues. And those values convert to 140.43 ppm to 280.86 ppm Si. Plants commonly have higher Si content (by tissue assay) than Ca, Mg, S, P, even total N in some cases. Plants can use lots of Si without problems.

A few conversions I made to help:

• 1 mmol/L Si = 28.0855 ppm Si
• 1 ppm Si = 0.0356 mmol/L Si
• 1 mmol/L H4SiO4 = 96.115 ppm H4SiO4
• 1 ppm H4SiO4 = 0.01 mmol/L H4SiO4
• 1 ppm Si = 3.42 ppm H4SiO4
• 1 ppm H4SiO4 = 0.292207 ppm Si
  • and two useful equations:
  • (mmol/L)molar mass = ppm
  • (mg/L)/molar mass = mmol/L

One reason I used ~1 mM Si with Pro-TeKt is the price, and I'm not sure how accurate the data is for % K20 and % SiO2 on Pro-TeKt's label. Currently my formulations use between 2.848 mmol/L Si to 3.204 mmol/L Si.

I wanted to use less than 100 ppm of Si, but to keep S (sulfate) below 110 ppm. That meant I had to increase the AgSil 16H (in early-flowering) to (at least) 90 ppm Si.

I increased Si during vegetative phase, from my previous ppm of ~30, because further testing on cannabis shows plants respond well to > 30 ppm. Many cannabis growers use 100 ppm SiO2, which converts to 46.7435 ppm Si. I also increased Si because it seems more people are having issues with PM, and increasing Si will help hinder PM.

I increased Si in early-flowering and full-flowering because of the increased cell growth/elongation vs vegetative stage. As well as because trichome of the Genus Cannabis are highly "silicaifed", that is, trichomes are compromised of much silicon (or would it be silica?), possibly as SiO2 (silicon dioxide), the common form of silicon once H4SiO4 is 'absorbed' and converted by the plant. Plants 'take in' orthosilicic acid (H4SiO4) and then convert it to SiO2, and maybe other forms of which I'm unaware. I also increased Si do help with PM in flowering stages.

• Here are some good screenshots from a couple of studies and rep reports:

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NOTE:
We give our plants silicon, not silica. I would not wish to use any product that's potassium silicate and has "silica" in the label, ex., "Silica Blast". If the manufacturer doesn't understand that key difference I don't have much faith in the quality their product.



In vegetative and "early-flowering" stages I am using 30 ppm P. In "full-flowering" stage I am using 87 ppm P. I increased the P from 30 ppm (sufficient range, albeit a bit high) to 87 ppm after pre-flowering stretch and after initial flower-set, ie., what I term "early-flowering" stage. Once plants are past initial flower-set, the stage I term "full-flowering" stage, I increase P because doing so may increase THC.

I have read one good study, and a second okay study, on effects from various application rates of N, P, K, etc., on THC. In one good study, the researchers found increased P (and reduced K) was strongly correlated to increased THC. The authors hypothesized increased P may affect enzyme pathway thereby increasing THC-A, IIRC. However, they did not quantify glandular trichome density (trichs per mm^2), they only carried out quantification assay on extract. I personally feel increased P may increase trichome density, due to the reports by other cannabis growers; if so, the THC quantity would also increase.

In the future I plan to carry out very well designed and controlled studies to see if increasing P does increase THC-A and trichome density. For now I am covering my bases by increasing P, as well as increasing pH buffering.

The biggest reason to keep P at sufficient level of ~20-40 ppm is to reduce internodal elongation, and to increase root growth (i.e., reduce the "root:shoot ratio"). By the time full-flowering stage arrives the roots are pretty much done growing (elongating), as are shoots.

I plan to test 20 ppm P with use of AM (arbuscular mycorrhizae) fungi. I have written very much on this topic, and I'm the one who blew apart the myth about high efficacy of AM fungi in cannabis growth with P greater than ~30 ppm. If we plan to use AM fungi we need to keep P below 25 ppm, ideally below 20 ppm.




As we know, ion ratios are about antagonisms and potentiations, so they are quite important. As are the sources of elements, which is why I will not use MAP (mono-ammonium phosaphte) if I can help it, and will instead use DAP (di-ammonium phosphate). DAP is higher purity and has less contamination than MAP, there are industry standards for DAP and not so for MAP. That is why I choose DAP and not MAP.

I choose the ratio of 4, for NO3:NO4, because of the buffering effect on pH (from lower ratio) and impact on plant usage of increased CO2 from ammonium (NH4). I kept the ratio of 4 for all stages of growth. Ideally, a ratio of 3 is better in terms of pH and CO2 (re ppm of NH4). However, plants in warm conditions and bright light, esp. flowering and fruiting plants where the "photosyntate" stays close to the source tissue (i.e., leafs and flowers) the plant is less able to move carbohydrates (sugar) to roots to convert NH4 into amino acids. In such a case a ratio above 3 is ideal to prevent phytotoxicity and poor growth.

In terms of effect from NO3:NH4 ratio on pH in rhizosphere and soilless solution, or reservoir (for water culture), we must consider root exudates. As roots 'take in' the anion nitrate (NO3), they release (exude, re exudate) bicarbonates, etc., which increases pH (as well as alkalinity), however, when roots 'take in' urea (fwiw, they can in fact take in small amounts) or the cations ammonicial nitrogen (ammonia (NH3) and ammonium (NH4), they release H+ protons which reduce pH and alkalinity. Thus, by reducing the NO3:NH4 ratio (when all ammonicical N is NH4) close to 1, we in effect reduce pH swings by better balancing acidic and basic exudates from roots.

However, one must consider the process of "nitrification", whereby NH4 is converted into nitrite (NO2) and NO2 is then converted into NO3 (nitrate). This process happens quite fast and has high efficacy when there are copious microbes able to carryout the conversion, such as "nitrifying bacteria" species, which are highly ubiquitous. That means unless we use something like chlorine dioxide at 0.25-0.5 ppm or hydrogen peroxide, much NH4 will be converted into NO3, thereby increasing the NO3:NH4 ratio.

There is also the topic of antagonisms and potentiations of NO3, by NH4. That is, at first (couple of house) NH4 potentiates uptake of NO3, however, after some times (hours/days) NH4 antagonizes uptake of NO3. I used a NO3:NH4 ratio which should reduce the effects of NH4 on NO3, vs ideal ratio of 3 (in terms of pH).

In terms of the long term effects of increased CO2 the higher the NH4 ppm the better, within reason. Please see this thread I wrote about CO2 for much more information on this topic: The facts about CO2 ppm: don't use 1,500!

• Here is a screenshot from a good report showing the process of nitrification (left hand side) and the effect of urea and various ionic species of nitrogen on root exudates and thus upon pH and alkalinity:

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I choose a K:Mg ratio of 3 because the ppm of K has a stronger effect (antagonization) of Mg than Ca. I kept the ratio of 3 for K:Mg in all stages of growth. I would have kept a ratio of 1.5 for K:Ca, however, that would have increased NO3 too far and messed up my NO3:NH4 ratio.

I try to use at least a ratio of 2.5 for K:Ca, and high ppm Ca because plants 'take up' Ca slower than almost every other element, and Ca-P precipitation can/will form in rhizosphere (AFAIK) thus reducing available Ca.

I boosted K to 230 ppm in early-flowering (and boosted Mg to keep the ratio of 3), which may or may not help yield. Many growers believe boosting K can increase yield, myself included. I reduced K back to ~200 ppm for full-flowering just in case increased K can reduce THC. Using the fertilizer compounds I choose, I can boost K but not increase P at all

I choose a Ca:Mg ratio of equal to or less than 2 because that ratio has worked very well for me and many other growers.

I choose high S (sulfate) because it's my "degree of freedom" element in HydroBuddy, thereby allowing me to create a more accurate formulation. Also, sulfate is commonly used up to ~120 ppm in academic and commercial hydroponics. My goal was to keep S below 110 ppm. Also, because S affects smell I increased S to help increase terpene action to increase smell (I'm not positive of the chemical steps or the science). I decreased S during full-flowering to affect the P:S ratio, to reduce possible antagonism of P by S.

Okay, I think that about covers the most important topics. If I forgot something please feel free to let me know.


NOTE:
As plants near time to harvest I start decreasing EC, as reported by NSCU FloraCulture "PourThru" methodology (when using soilless - the PourThru method isn't need for water culture). Using any other method, ex., haphazardly testing run-off as most growers do, provides very inaccurate EC results. That means nearly every soil and soilless cannabis grower doesn't now the real EC of the rhizosphere and soilless solution unless they use PourThru (or other proven methods*). However, use of "suction lysimeters" allow for even greater accuracy of EC and pH from soilless soition ...

* Other methods to accurately test EC and pH of soilless solution are a no go for living plants, ex., "SME", "1:2", "1:5", etc. Also, due to differences in each methodology one must use conversion factors to compare EC from NCSU PourThru to SEM to 1:2, etc.

AHHH Feels good to have Spurr back.

Originally Posted by spurr

The authors hypothesized increased P may affect enzyme pathway thereby increasing THC-A, IIRC. However, they did not quantify glandular trichome density (trichs per mm^2), they only carried out quantification assay on extract. I personally feel increased P may increase trichome density, due to the reports by other cannabis growers; if so, the THC quantity would also increase.

In the future I plan to carry out very well designed and controlled studies to see if increasing P does increase THC-A and trichome density.

DOPE. are Jasmonates going to be part of the test and where do i get the tool that allows me to properly measure mm^2? My personal experiences have led me to believe that increased P does allow for more trichome production to take place as well.

[spurr]

Originally Posted by DonkDBZ

I mean will using sugars, fulvic, enymes and other plant extracts in my dtw res defeated the purpose of preping the water as u suggest

Nope. There shouldn't be any antagonisms, at least none I foresee.

I suggest not using any amino acids though (besides DON if you wish - Dissolved Organic Nitrogen). Many amino acids will hinder NO3 uptake and P uptake and unless the plant is under stress it makes all the amino acids it needs. Some will increase NO3 uptake and some won't affect NO3 uptake. I made a list of some amino acids that affect NO3 uptake if you'd like to see it.

You may also want to test the efficacy of enzymes you use, if you mean something like CannaZyme. The reason I make such a suggestion is many enzymes will rather quickly 'breakdown' (become denatured) and no longer work. So in some cases using them is a waste.

Originally Posted by DonkDBZ

Also useing your method to prep the water making some sort of chemical reaction or what major benefits vs most people adding nutes then using ph up or down.

By simply adding pH up or pH down we aren't affecting alkalinity (for pH buffer against acidic swings) nor are we affecting pH buffer against basic pH swings. All pH adjusting water does is make it so as many ions stay in solution as possible. Besides that, it really has nothing to due with plant uptake. If we could make equal number and species of ions be in solution (i.e., plant available) at pH 4.5, pH 6.0 and pH 8.0, most plants would do equally well at all ranges.

It's a myth that pH of water affects pH of soilless solution and/or media and/or plant uptake, besides keeping ions in solution, i.e., dissolved when in reservoir (when we can change the pH). This is why organic growers have success when pH is 8.0 and higher. The exceptions when water pH does affect pH of soilless solution/media and alkalinity are when the pH is very acidic very basic pH, ex., < pH 4 and > pH 10.

What that means is to keep pH buffered in a reservoir or media (i.e., soilless solution) we need to worry mainly about acidic buffer like alkalinity, NO3:NH4 ratio, K ppm (it lowers pH) and basic buffer like citrate/citric acid. The pH of the water is of very little consequence in terms of pH buffering and plant growth esp. in soilless media.

That means for most growers their water has very little pH buffering ability, and once the roots start exuding acids and bases the pH will move a lot. That is why many people have to adjust pH everyday or every few days: root exudates, carbonic acid and low basic and acidic pH buffering.

Here is a good article on this topic, it's more geared toward soilless growers of media the holds water like coco, peat, rockwoll, etc. However, there is a lot of useful info there, and it's a good intro, so growers that use water culture should get benefit from reading the article:

Understanding Plant Nutrition: Irrigation Water Alkalinity & pH
Agro and Fisher take a microscope to the details that can help growers make informed decisions on nutrients.
By Bill Argo and Paul Fisher (May 2008)
https://www.greenhousegrower.com/magazine/?storyid=96

Originally Posted by DonkDBZ

Currently I am using RO putting protek in 1st then floranova grow then calmag then sweet

Do you adjust pH after adding Pro-TeKt?

Originally Posted by DonkDBZ

next question is the orthosilicic acid in addition to protek or ahsil 16h?

Nope, the SiO2 from any source of potassium silicate becomes orthosilicic acid (H4SiO4) after it mixes with water. That is why using Dutch Master Gold Range Silica is a rip off. It's already mixed with water so has low Si content.

What I wrote about orthosilicic acid was only to point out that plants do not 'take in' SiO2 (silicon dioxide) nor Si (silicon); neither are plant bioavailable. The plant bioavailable source of silicon is orthosilicic acid (H4SiO4), aka monosilicic acid, aka silicic acid.

I hope that answers your questions, if not let me know.

[spurr]

Originally Posted by iSMOKE.KUSH

also whats the best price anyone has seen on DAP?

I found ~$7 per pound on Ebay last week, IIRC. It's amazing how much money you save on fertilizer when you use dry compounds and mix your own, hundreds, easily. Hydro-Gardens sells it but only by 50 pounds for ~$127.00. Hydro-Gardens is very overpriced ...

Also, the owner of Hydro-Gardens is very anti-cannabis, from what I've been told. If you mention you are growing cannabis he may not do business with you, however, I heard that playing the telephone game so take it with a grain of salt ...

p.s. just about to harvest my first full round using spurrs current profile (5/5/7/5/2.5/.5g), and it is looking stellar. 16 lights of some of the nicest looking flowers i've grown to date. mucho excited..

I'm happy for you, I'm glad it's serving you well

[Grizz]

way to much for me to understand, really wish you would do us all a favor and just make the nutes and sell them .

[spurr]

Ha. I have thought about that, I have. I have a feeling someone/some company might steal my methods and do the same, sell it retial ...