Dr. Fernandez...I absolutely love your videos....I am looking into trying to mix my own organic mediums and nutrients for hydroponics...your reports on rice hulls really caught my eye...anytime i see a completely renewable source it brightens up my day.....you do incredible work...and God has blessed you with an amazing mind!
Dr. Fernandez, the rice hulls are used as is? here in the Philippines, we burn rice hull to ash and you get a bit of potassium and lots of silica. we add some boron. we dilute the solution of course. and now your plant transport system is good...blessings to all
Coco coir and amendments. Are there any special issues with Ca/Mg in coco if wollastonite is used? I've fired off an email to USU requesting a discussion on specific coco requirements in the current course. The implication from coco manufacturers is that their special nutrients must be used.
what about amorphous silica(SiO2) that releases plant available silicon in the form of monosilicic acid ? We have found the 5mm chip a great medium for Hydroponics
Amorphous silica will not appreciably dissolve or contribute Si to the plant, except perhaps when we're talking about silica nanoparticles with sizes below 20nm.
to add magnesium as you mention, adding dolomitic lime in the fall and horse manure, as well as wollastonite in the spring, will that compensate for the fixation of magnesium and nh4? or is it not indicated?
Hi Dr. Fernandez, all the info you have put out on Silica was much needed and helpful!!! Thank you!!!! We grow with vermiponics and all our nutrient strategies must be built around sovereignty (not relying on anything imported from more than 30 min drive, everything locally accessible). This is for our own resilience from a destabilizing global economy and so that our methods can be adopted anywhere in the world that doesn't have the import access that United States have. I'm trying to develop a protocol for sovereign silicate. How does this sound? Here's what I understand so far. magnesium silicate and calcium silicate are not soluble, so need to use a lot. Potassium silicate is ideal and sodium silicate is good enough. Because silica is a trace element, using sodium silicate is probably fine. Target plant sap Na levels are ~100ppm and Si levels are 10ppm, so giving the plant 10ppm of silica would only increase the sodium by 20ppm, not great, not bad either. Potassium silicate and sodium silicate are very soluble. They are made by melting potassium carbonate or sodium carbonate in a crucible at 1600F and 1500F respectively. You start with potassium bicarbonate from a sunflower shell ash or ash of something rich in potassium like banana peels (at 600F the potassium bicarbonate becomes potassium carbonate...At 120F the sodium bicarbonate becomes sodium carbonate) We could use cast iron or stainless steel as crucibles, which has a melting temp of 2200F and 2500F respectively. Then you add silicon dioxide(glass/silica/sand) to the melt. (Silicon dioxide melts at 3300F btw). The melted carbonates will dissolve the glass and form potassium silicate or sodium silicate. Let it cool. You can leave as a powder or put it in water w/ more potassium carbonate...the potassium carbonate solution will prevent the potassium silicate from polymerization/precipitating? The max temp of a campfire is considered to be 1650F...it's questionable if this work can be done casually on an open wood fire. I like doing hydroponic witchcraft on a campfire because, it turns a job into an experience to create connection within community and then the community becomes invested in food production...always good for your heart and business. We tell our friends to save all their banana peels, invite them over for a fire, burn a pile of banana peels, inside a cast iron pot, on top of a wood fire...the wood fire is contributing most of the heat, but the pot keeps the peel ash separate. Then put the peel ash in a small cast iron pot or other crucible. Get the fire hot and keep crucible in hottest part of fire. When the peel ash(potassium carbonate) starts to boil, put broken glass in it. Once glass has dissolved, take off of fire. My 1st concern is if the calcium carbonate in the peel ash would steal the silicate from the potassium carbonate...but I'm guessing once all the calcium carbonate has reacted to form calcium silicate, then all the rest would become potassium silicate, so as long as there's plenty of silica available, you'll still get complete reactivity of the potassium carbonate. My 2nd concern is if you'll get some other random biproducts from all the other minerals in the peels and cast iron, that are either harmful or just interfere with the process. thoughts?
Thanks for commenting. The process you describe is very energy intensive, it is likely not a practical solution and the quality of the produced silicates will be difficult to establish. Amending media with rice hulls or Wollastonite are both likely better choices. There are several other amendments you can use, I would find which slow release silicon containing amendments are local to your area and use those instead.
@@ScienceinHydroponics Thanks! The internet says that grass has about 2%-5% silica levels by dry weight, approx 20 times most vegetables. Grass clippings are abundantly free. You think if we put grass clippings in our vermiculture, the plants will be able to take it up? I imagine it would have the same availability as rice hulls. Also, found horsetail that has has 10%-25% silica levels. Possible worth growing a patch of that as an amendment to the vermiculture?
Thanks for your reply! Certainly, grass clippings - once dried - will likely provide ample Si. Rice is also a monocot - so technically a type of grass - so basically any residue from a monocot is bound to work as a silicon supplement. Note that these plants might also contain other substances, so I wouldn't recommend using them as a supplement without testing first.
@@ScienceinHydroponics Thank you for this! We have started trials supplementing a)wheat straw and b)organic lawn clippings. I will update in a few months.
It does not provide much Si as it is fundamentally insoluble. Bear in mind, this mineral deposited in the ocean and remained stable for thousands of years under water.
This is fantastic and mirrors a lot of my own research. There are a couple things “missing” which I wish were talked about: 1) in many parts of the world that produce rice husk as a biproduct, it can be more easily found as a char (burnt), and I believe this may be more effective and superior in some use cases, and is also easy to produce from raw husks if that’s what is available. 2) while you warned against adding more than 3% of wollastonite, you did not give direct suggestions of addition quantity. I’m also curious if the increased nitrogen and magnesium would be recommended across the entire season, because that is quite a large increase in Mg. Thank you so much for the video! 🙏
Thanks for your comments and suggestions! About your comments: 1. Charring rice hulls increases their moisture retention and makes them a better amendment for some purposes, but turns a lot of the Si into SiO2, which will not go into solution. When used as an Si amendment, my advice would be to avoid charring the rice hulls. 2. I do give indications of how much to add. In case you missed it, it is around 1-3% v/v. This means, for every liter of media, add 10-30mL of wollastonite. 3. This depends on your environment and water use efficiency. Tissue analysis would be needed to determine whether the increase is needed only in the beginning or through the entire crop cycle. Also, thanks a lot for your support!
@@ScienceinHydroponics Thank you very much for your reply. Thanks for pointing out your usage suggestion. Regarding the charred rice husk, I can see the logic in your statement but I think you may not be considering all factors. There are multiple types of rice husk char and I believe the more common one to find commercially is "black rice husk ash" which is a lower temperature charcoal process that retains the silica in a "highly porous" amorphous structure. Based on my searches, this silica is present as very high surface area nanoparticles. Also, note that one of the links in your video leads to a study that used rice husk char/ash, but unfortunately I do not have access to journals so I cannot read the entire article. I'm willing to consider that you may be correct about raw/parboiled rice husk being better, but my intuition would be that charred husk would "free up" the silica from the cell walls as well as providing the other benefits of biochar such as ion exchange and pH buffering. Where I was spending some time farming, in Thailand, rice husk is mainly available in two formats, truly raw (which comes with some % of rice grains, and without composting can result in sprouts, mold, and organic chemical residues) and charred (a jet black product). I wish I had the resources to perform my own study so that I could determine the actual effects of incorporating either version and perhaps wollastonite as well.
Thanks for your reply. I definitely do not recommend to use raw/uncomposted rice hulls, due to the issues you mentioned. Parboiled rice hulls are the best choice if those are available. If not, then proper composting of rice hulls is necessary before they are used. In the case of parboiled Vs charred rice hulls as a silicon amendment, I couldn't find any studies comparing both directly, so I cannot provide you with direct evidence for one or the other. However, while having SiO2 nanoparticles does increase surface area a lot, it might not lead to better uptake. This is given that freely soluble Si chemical species are taken up much faster than nanoparticles and I would expect these to be present more abundantly when parboiled rice hulls are used, because the Si hasn't been transformed entirely to SiO2 and can form freely soluble Si species. In this review of Si uptake, you can see the differences between uptake for Si nanoparticles and other forms of Si (www.mdpi.com/2223-7747/8/6/148/htm). So while the Si is "free" in charred rice hulls it ends up in chemically less available forms (this would be my hypothesis). While evidence to the contrary is gathered, I will favor parboiled rice hulls over charred when talking about using them as a silicon amendment. Nonetheless, Wollastonite is my preferred amendment, due to it's much better Si release compared to both types of rice hulls. Of course, if substantial evidence arises of charred rice hulls being more effective as an Si amendment, I will certainly change my choice. Thanks a lot for contributing to the discussion, I appreciate your thoughts!
@@ScienceinHydroponics thanks for your input. I’ll definitely let you know if I come across any direct comparisons or if I eventually do it myself. 👍 I have a question about the best wollastonite form, because it is sold in different grades (finenesses), but I should probably ask as a new comment. Keep a look out :)
Which form of wollastonite do you think is the best? Or are different ones good for different purposes? I noticed the most common manufacturer Vansil sells w-10,20,30, and 40 which I believe are in order of coarse to fine. W-10 is the least expensive and the most coarse, but perhaps is not the best choice for short term use hydroponic media. Perhaps the best for hydro would be the very fine grades?
Thanks for commenting. I honestly haven't tested them all or seen comparisons, so I cannot tell you the expected differences in Si release. However, most commonly I've used W-10 with good results. It is likely you can use W-40 at a lower quantity and get similar results due to the faster release as a result of the larger surface area.
Thanks for commenting. Generally you would want to incorporate it in the media before transplant. If you it after you can top dress it, but the release will be less efficient.
Sadly it is not viable to use wallostonite in DWC. For DWC I would recommend you use a soluble Si source, like potassium silicate at a concentration of around 10 ppm of Si as elemental Si.
H Daniel, there was an error trying to send a message to you on your website, I copied and pasted here: , I am interested in booking a consultation with you. I am growing in coco and need advice regarding manipulation of pH. However, here in New Zealand we have very little choice when it come to buying nutrients and fertilizer. I presume your advise may include customizing the nutrients, this will be impossible without finding an international supplier of nutrients. I have spent considerable time searching, Amazon is frequently out of stock of most things I have searched for. Have you come good international supplier? Thanks
Thanks for commenting. No, charring the rice hulls increases the water retention of the media (so makes it better as a sole media in hydroponics) but this turns the silicon into silicon dioxide (SiO2) which isn't easily available. To be used as an Si amendment, the rice hulls should not be charred but just parboiled.
Hi, I had done experiment with using 20% burnt(char) rice hull + cocopeat as growing medium for kale. Transplanted in pot, hand water with AB solution. The result is pretty bad because pH spike up above 8 and i got to correct it with lots of phosphoric acid. I have not tried with raw rice hull, but will experiment with it soon.
@@ScienceinHydroponics plants somehow extract silica in the soil aggregate. Particularly, rice, sugar cane and grasses can extract a lot of "unavailable" silica from the soil. Of course, those are organic systems, and in a conventional/chemical hydroponic system, I suspect it's missing the symbiotic biology to deliver silica even if the growing media was sand. But, if it's an organic hydroponic system and the growing media is sand, shouldn't the plant have the same ability to absorb silica as it does in soil? (though I suppose a cubic inch plug is 1000x less silica volume than a cubic foot of soil root space). thoughts?
You mentioned it releasing slowly. So if I add 3% to the media it will release for the entire grow season? Would it still be available next season if I’m reusing soil? Also does this provide enough calcium so don’t feed with a nutrient like jacks 321 that already contains calcium?
How quickly it goes away will depend fundamentally on how much you irrigate and how much runoff you get, as this determines the leaching rate. The amount won't be enough to replace a soluble calcium source. Calcium silicate should not be considered a calcium supplement, although it does provide some calcium.
Great video! I would like to ask if fertigating with hypochlorous acid will cause problems with wallastonite in the media. And also if I'm using with dechlorinated tap water with a discrete amount of Calcium Carbonate will affect the availability of Silicon. Using tap water is it suggest to rise even more Ammonial N to compensate for the higher pH (maybe 15 ppm more)? Thanks in advance!
Thanks for commenting! Wallostonite increases the pH, but if you allow this to happen then the release of the Si ends. This is because the reaction for Si release is heavily dependent on pH and becomes slower as the pH increases. For this reason the media needs to be kept at 5.6-5.8 in order for the release of Si to be continuous and effective. Adding some ammonium would help you achieve this, how much depends on your total N. About hypochlorous acid, this will not be a problem. I hope this is helpful!
@@ScienceinHydroponics thanks for the answer! Regarding N intake we are talking about ~140 elemental PPM. Is 10% ammoniacal N enough? Unfortunately my dechlorinated tap buffers pH quite a bit I can't stay under 6.3 pH unless I push dry backs in my coco harder,but the EC rise gives me far worse problems then having a higher substrate PH. I'm considering on switching to 80%RO and 20% tap but I have to find first efficient RO units that don't make me waste a ton of water. Bills must be paid lol
Thanks for your reply. There's no need to switch to RO, in most of these cases a custom solution can be made to solve any issues. This is too extensive to answer here though, I would encourage you to book an hour of consulting on my website (scienceinhydroponics.com/book) if you would like to have my help in solving your issue.
Thanks for commenting. The GH Armor Si is a dissolved potassium silicate. You can buy much cheaper and concentrated products, AgSil 21 or if you want a solid you can buy AgSil 16H and dissolve it to prepare a liquid concentrate. It is very hard to overdo Si, because when you overdo it, it will fall out of solution and the plant won't get it. However, you might be able to do so if you use a stabilized ortho Silicic acid product. However, I do not know what the symptoms or consequences of an Si toxicity are.
What are your thoughts on mono and di silicic acid for quick crops in soilless media? Is it too expensive for commercial production? Is it just snake oil? Everytime a grower hears "immediately bioavailable" we just open our wallets, so I'm curious your thoughts on the subject.
Thanks for commenting. So far, no peer reviewed study - that I am aware of - has showed stabilized mono/di silicic acids to perform better than just simple soluble silicates (like potassium silicate) to increase Si in tissue or to provide better yields. These slow releasing amendments also provide adequate Si to tissue, not as much as what you get with K silicate, but more than enough to get most of the benefits of Si supplementation.
Dr. Fernandez...I absolutely love your videos....I am looking into trying to mix my own organic mediums and nutrients for hydroponics...your reports on rice hulls really caught my eye...anytime i see a completely renewable source it brightens up my day.....you do incredible work...and God has blessed you with an amazing mind!
Thank you very much for all your kind words. Your message made my day.
Dr. Fernandez, the rice hulls are used as is? here in the Philippines, we burn rice hull to ash and you get a bit of potassium and lots of silica. we add some boron. we dilute the solution of course. and now your plant transport system is good...blessings to all
Coco coir and amendments. Are there any special issues with Ca/Mg in coco if wollastonite is used? I've fired off an email to USU requesting a discussion on specific coco requirements in the current course. The implication from coco manufacturers is that their special nutrients must be used.
I haven't noticed any special issues when using wollastonite in coco, the amendment is usually quite small compared to the bulk volume of the media.
Great content Daniel, keep going, learning a lot.
Thanks for commenting!
so just for verification, diatomaceous earth will not work as a silicon supplement? i recently swapped to woolastinite though based on research
what about amorphous silica(SiO2) that releases plant available silicon in the form of monosilicic acid ? We have found the 5mm chip a great medium for Hydroponics
Amorphous silica will not appreciably dissolve or contribute Si to the plant, except perhaps when we're talking about silica nanoparticles with sizes below 20nm.
to add magnesium as you mention, adding dolomitic lime in the fall and horse manure, as well as wollastonite in the spring, will that compensate for the fixation of magnesium and nh4? or is it not indicated?
Hi Dr. Fernandez, all the info you have put out on Silica was much needed and helpful!!! Thank you!!!!
We grow with vermiponics and all our nutrient strategies must be built around sovereignty (not relying on anything imported from more than 30 min drive, everything locally accessible). This is for our own resilience from a destabilizing global economy and so that our methods can be adopted anywhere in the world that doesn't have the import access that United States have. I'm trying to develop a protocol for sovereign silicate. How does this sound?
Here's what I understand so far. magnesium silicate and calcium silicate are not soluble, so need to use a lot. Potassium silicate is ideal and sodium silicate is good enough. Because silica is a trace element, using sodium silicate is probably fine. Target plant sap Na levels are ~100ppm and Si levels are 10ppm, so giving the plant 10ppm of silica would only increase the sodium by 20ppm, not great, not bad either.
Potassium silicate and sodium silicate are very soluble. They are made by melting potassium carbonate or sodium carbonate in a crucible at 1600F and 1500F respectively. You start with potassium bicarbonate from a sunflower shell ash or ash of something rich in potassium like banana peels (at 600F the potassium bicarbonate becomes potassium carbonate...At 120F the sodium bicarbonate becomes sodium carbonate) We could use cast iron or stainless steel as crucibles, which has a melting temp of 2200F and 2500F respectively. Then you add silicon dioxide(glass/silica/sand) to the melt. (Silicon dioxide melts at 3300F btw). The melted carbonates will dissolve the glass and form potassium silicate or sodium silicate. Let it cool. You can leave as a powder or put it in water w/ more potassium carbonate...the potassium carbonate solution will prevent the potassium silicate from polymerization/precipitating?
The max temp of a campfire is considered to be 1650F...it's questionable if this work can be done casually on an open wood fire. I like doing hydroponic witchcraft on a campfire because, it turns a job into an experience to create connection within community and then the community becomes invested in food production...always good for your heart and business. We tell our friends to save all their banana peels, invite them over for a fire, burn a pile of banana peels, inside a cast iron pot, on top of a wood fire...the wood fire is contributing most of the heat, but the pot keeps the peel ash separate. Then put the peel ash in a small cast iron pot or other crucible. Get the fire hot and keep crucible in hottest part of fire. When the peel ash(potassium carbonate) starts to boil, put broken glass in it. Once glass has dissolved, take off of fire.
My 1st concern is if the calcium carbonate in the peel ash would steal the silicate from the potassium carbonate...but I'm guessing once all the calcium carbonate has reacted to form calcium silicate, then all the rest would become potassium silicate, so as long as there's plenty of silica available, you'll still get complete reactivity of the potassium carbonate.
My 2nd concern is if you'll get some other random biproducts from all the other minerals in the peels and cast iron, that are either harmful or just interfere with the process.
thoughts?
Thanks for commenting. The process you describe is very energy intensive, it is likely not a practical solution and the quality of the produced silicates will be difficult to establish. Amending media with rice hulls or Wollastonite are both likely better choices. There are several other amendments you can use, I would find which slow release silicon containing amendments are local to your area and use those instead.
@@ScienceinHydroponics Thanks! The internet says that grass has about 2%-5% silica levels by dry weight, approx 20 times most vegetables. Grass clippings are abundantly free. You think if we put grass clippings in our vermiculture, the plants will be able to take it up? I imagine it would have the same availability as rice hulls. Also, found horsetail that has has 10%-25% silica levels. Possible worth growing a patch of that as an amendment to the vermiculture?
Thanks for your reply! Certainly, grass clippings - once dried - will likely provide ample Si. Rice is also a monocot - so technically a type of grass - so basically any residue from a monocot is bound to work as a silicon supplement. Note that these plants might also contain other substances, so I wouldn't recommend using them as a supplement without testing first.
@@ScienceinHydroponics Thank you for this! We have started trials supplementing a)wheat straw and b)organic lawn clippings. I will update in a few months.
@@darknectarcooperative7242avez-vous des nouvelles sur vos recherches, je suis curieux des résultats de vos recherches!
Do you have any data on Food Grade Diatomaceous Earth and its PAS? Does it provide ample SI.
Thank you.
It does not provide much Si as it is fundamentally insoluble. Bear in mind, this mineral deposited in the ocean and remained stable for thousands of years under water.
This is fantastic and mirrors a lot of my own research. There are a couple things “missing” which I wish were talked about:
1) in many parts of the world that produce rice husk as a biproduct, it can be more easily found as a char (burnt), and I believe this may be more effective and superior in some use cases, and is also easy to produce from raw husks if that’s what is available.
2) while you warned against adding more than 3% of wollastonite, you did not give direct suggestions of addition quantity.
I’m also curious if the increased nitrogen and magnesium would be recommended across the entire season, because that is quite a large increase in Mg.
Thank you so much for the video! 🙏
Thanks for your comments and suggestions! About your comments:
1. Charring rice hulls increases their moisture retention and makes them a better amendment for some purposes, but turns a lot of the Si into SiO2, which will not go into solution. When used as an Si amendment, my advice would be to avoid charring the rice hulls.
2. I do give indications of how much to add. In case you missed it, it is around 1-3% v/v. This means, for every liter of media, add 10-30mL of wollastonite.
3. This depends on your environment and water use efficiency. Tissue analysis would be needed to determine whether the increase is needed only in the beginning or through the entire crop cycle.
Also, thanks a lot for your support!
@@ScienceinHydroponics Thank you very much for your reply. Thanks for pointing out your usage suggestion.
Regarding the charred rice husk, I can see the logic in your statement but I think you may not be considering all factors. There are multiple types of rice husk char and I believe the more common one to find commercially is "black rice husk ash" which is a lower temperature charcoal process that retains the silica in a "highly porous" amorphous structure. Based on my searches, this silica is present as very high surface area nanoparticles. Also, note that one of the links in your video leads to a study that used rice husk char/ash, but unfortunately I do not have access to journals so I cannot read the entire article.
I'm willing to consider that you may be correct about raw/parboiled rice husk being better, but my intuition would be that charred husk would "free up" the silica from the cell walls as well as providing the other benefits of biochar such as ion exchange and pH buffering. Where I was spending some time farming, in Thailand, rice husk is mainly available in two formats, truly raw (which comes with some % of rice grains, and without composting can result in sprouts, mold, and organic chemical residues) and charred (a jet black product). I wish I had the resources to perform my own study so that I could determine the actual effects of incorporating either version and perhaps wollastonite as well.
Thanks for your reply.
I definitely do not recommend to use raw/uncomposted rice hulls, due to the issues you mentioned. Parboiled rice hulls are the best choice if those are available. If not, then proper composting of rice hulls is necessary before they are used.
In the case of parboiled Vs charred rice hulls as a silicon amendment, I couldn't find any studies comparing both directly, so I cannot provide you with direct evidence for one or the other.
However, while having SiO2 nanoparticles does increase surface area a lot, it might not lead to better uptake. This is given that freely soluble Si chemical species are taken up much faster than nanoparticles and I would expect these to be present more abundantly when parboiled rice hulls are used, because the Si hasn't been transformed entirely to SiO2 and can form freely soluble Si species.
In this review of Si uptake, you can see the differences between uptake for Si nanoparticles and other forms of Si (www.mdpi.com/2223-7747/8/6/148/htm). So while the Si is "free" in charred rice hulls it ends up in chemically less available forms (this would be my hypothesis).
While evidence to the contrary is gathered, I will favor parboiled rice hulls over charred when talking about using them as a silicon amendment. Nonetheless, Wollastonite is my preferred amendment, due to it's much better Si release compared to both types of rice hulls.
Of course, if substantial evidence arises of charred rice hulls being more effective as an Si amendment, I will certainly change my choice.
Thanks a lot for contributing to the discussion, I appreciate your thoughts!
@@ScienceinHydroponics thanks for your input. I’ll definitely let you know if I come across any direct comparisons or if I eventually do it myself. 👍
I have a question about the best wollastonite form, because it is sold in different grades (finenesses), but I should probably ask as a new comment. Keep a look out :)
Which form of wollastonite do you think is the best? Or are different ones good for different purposes? I noticed the most common manufacturer Vansil sells w-10,20,30, and 40 which I believe are in order of coarse to fine. W-10 is the least expensive and the most coarse, but perhaps is not the best choice for short term use hydroponic media.
Perhaps the best for hydro would be the very fine grades?
Thanks for commenting. I honestly haven't tested them all or seen comparisons, so I cannot tell you the expected differences in Si release. However, most commonly I've used W-10 with good results. It is likely you can use W-40 at a lower quantity and get similar results due to the faster release as a result of the larger surface area.
W-10 1 gram per liter
Brilliant. Thank you so much... can I add wollastonite after I transplant? ie top dress or slurry it through media?
Thanks for commenting. Generally you would want to incorporate it in the media before transplant. If you it after you can top dress it, but the release will be less efficient.
Is there a way to use wollastonite in dwc if so how!
Sadly it is not viable to use wallostonite in DWC. For DWC I would recommend you use a soluble Si source, like potassium silicate at a concentration of around 10 ppm of Si as elemental Si.
At this rate 1 to 3% wallastonite how much in ppm are it realesing over time? Like rice hulls 7 to 10ppm of si?
More and faster. Read this masters thesis for more information on this topic digitalcommons.usu.edu/etd/8680/
H Daniel, there was an error trying to send a message to you on your website, I copied and pasted here: , I am interested in booking a consultation with you. I am growing in coco and need advice regarding manipulation of pH. However, here in New Zealand we have very little choice when it come to buying nutrients and fertilizer. I presume your advise may include customizing the nutrients, this will be impossible without finding an international supplier of nutrients. I have spent considerable time searching, Amazon is frequently out of stock of most things I have searched for. Have you come good international supplier? Thanks
Thanks for commenting. I received your message on my website, I'll reply to your email.
If we provide silicon as a foliar spray, do we still need to increase the mg and nh4???
No, but bear in mind Si is immobile so if you foliar feed, any tissue that grows after your spray will contain no Si.
Do you recommend charring the rice hulls?
Thanks for commenting. No, charring the rice hulls increases the water retention of the media (so makes it better as a sole media in hydroponics) but this turns the silicon into silicon dioxide (SiO2) which isn't easily available. To be used as an Si amendment, the rice hulls should not be charred but just parboiled.
Hi, I had done experiment with using 20% burnt(char) rice hull + cocopeat as growing medium for kale. Transplanted in pot, hand water with AB solution. The result is pretty bad because pH spike up above 8 and i got to correct it with lots of phosphoric acid. I have not tried with raw rice hull, but will experiment with it soon.
Thanks for putting this together! Does river sand in the plug grow media help increase uptake of silica?
No, silica in riversand is entirely inaccessible to plants.
@@ScienceinHydroponics plants somehow extract silica in the soil aggregate. Particularly, rice, sugar cane and grasses can extract a lot of "unavailable" silica from the soil. Of course, those are organic systems, and in a conventional/chemical hydroponic system, I suspect it's missing the symbiotic biology to deliver silica even if the growing media was sand. But, if it's an organic hydroponic system and the growing media is sand, shouldn't the plant have the same ability to absorb silica as it does in soil? (though I suppose a cubic inch plug is 1000x less silica volume than a cubic foot of soil root space). thoughts?
You mentioned it releasing slowly. So if I add 3% to the media it will release for the entire grow season? Would it still be available next season if I’m reusing soil? Also does this provide enough calcium so don’t feed with a nutrient like jacks 321 that already contains calcium?
How quickly it goes away will depend fundamentally on how much you irrigate and how much runoff you get, as this determines the leaching rate. The amount won't be enough to replace a soluble calcium source. Calcium silicate should not be considered a calcium supplement, although it does provide some calcium.
Great video! I would like to ask if fertigating with hypochlorous acid will cause problems with wallastonite in the media. And also if I'm using with dechlorinated tap water with a discrete amount of Calcium Carbonate will affect the availability of Silicon. Using tap water is it suggest to rise even more Ammonial N to compensate for the higher pH (maybe 15 ppm more)? Thanks in advance!
Thanks for commenting! Wallostonite increases the pH, but if you allow this to happen then the release of the Si ends. This is because the reaction for Si release is heavily dependent on pH and becomes slower as the pH increases. For this reason the media needs to be kept at 5.6-5.8 in order for the release of Si to be continuous and effective. Adding some ammonium would help you achieve this, how much depends on your total N. About hypochlorous acid, this will not be a problem. I hope this is helpful!
@@ScienceinHydroponics thanks for the answer! Regarding N intake we are talking about ~140 elemental PPM. Is 10% ammoniacal N enough? Unfortunately my dechlorinated tap buffers pH quite a bit I can't stay under 6.3 pH unless I push dry backs in my coco harder,but the EC rise gives me far worse problems then having a higher substrate PH. I'm considering on switching to 80%RO and 20% tap but I have to find first efficient RO units that don't make me waste a ton of water. Bills must be paid lol
Thanks for your reply. There's no need to switch to RO, in most of these cases a custom solution can be made to solve any issues. This is too extensive to answer here though, I would encourage you to book an hour of consulting on my website (scienceinhydroponics.com/book) if you would like to have my help in solving your issue.
Rice hull is in the burned or raw form?
Raw
Raw form, but parboiled. You don't want the completely raw form because it will ferment and cause issues because of its residual rice content.
What is your opinion on General Hydroponics Armor Si ? Also, can pepper plants get an Si toxicity? (can it be over done?)
Thanks for commenting. The GH Armor Si is a dissolved potassium silicate. You can buy much cheaper and concentrated products, AgSil 21 or if you want a solid you can buy AgSil 16H and dissolve it to prepare a liquid concentrate.
It is very hard to overdo Si, because when you overdo it, it will fall out of solution and the plant won't get it. However, you might be able to do so if you use a stabilized ortho Silicic acid product. However, I do not know what the symptoms or consequences of an Si toxicity are.
DOES SILICA HELP A DICOT LIKE CANNABIS YES OR NO
Yes.
Does usage of silicon affect the flavour of fruits and vegetables also???
Not that I know of.
What are your thoughts on mono and di silicic acid for quick crops in soilless media? Is it too expensive for commercial production? Is it just snake oil? Everytime a grower hears "immediately bioavailable" we just open our wallets, so I'm curious your thoughts on the subject.
Thanks for commenting. So far, no peer reviewed study - that I am aware of - has showed stabilized mono/di silicic acids to perform better than just simple soluble silicates (like potassium silicate) to increase Si in tissue or to provide better yields. These slow releasing amendments also provide adequate Si to tissue, not as much as what you get with K silicate, but more than enough to get most of the benefits of Si supplementation.