Prescription Blend Grows SweetSeeds in AutoPots - Test by Only1Sky

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Waira

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...you know, with that new pic, I think the Rx Blend mate here is onto something,... over all paleness isn't a Ca thing, and the spotting can look a great deal like P defc too, and both can hit at mid levels even though Ca is (nearly)immobile, P isn't,... here it's on a lower, so maybe it's more likely P defc... have you checked the in-pot pH 'Sky? that's my #1 suspect since you've been feeding well enough I believe,... Too acidic and P starts to lock out... I'm not surprised the MC plant is greener, may be the high N content....
Leaves have a bit of edge/teeth roll going on, light stress is suspect; how far from the lights are they?
 

Prescription Blend

Prescription Blend Plant Food for Medical Gardens
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@Only1Sky seeing the two Killer Kush next to each other is interesting. These seem to be really different phenotypes with the plant getting fed prescription blend having that longer node spacing. One observation is that the media looks drier in the yellow bag compared to the purple one. Since this plant got fed the same mix as the others we can rule out anything about the solution. The overall light shade of green and the spots on the oldest leaves make me think its hungry, I could be wrong about the media being direr then the other pot (hard to see in a pic) but I would go with a good watering of slightly higher strength nutrient.

As far as mixing order and this goes for any brand, the most important thing is to mix silica supplements first! Silicates in high enough concentration will polymerize to an insoluble form when combine with ionic compounds in solution and especially positively charged metals like Ca2+ and Mg2+. Mixing silica into your water first dilutes the silicates to a point that the polymerization is no longer possible. You can see this effect if you mix a silica after the main nutrients by noticing the little cloudyness that appears where you pour in the silica supplement.

@Waira we use several silica sources making Bio-Si. Rice plants are natural silica accumulators, we use a combination of silica from rice grain hulls and potassium silicate so it does raise the pH. When the other nutrients are added the pH settles down between about 5.8-6.4 depending on your starting water, the water used in the video was fairly alkaline to begin with. Some people like it a little higher and Bio-Si could be used to bring it up.

Update: @Only1Sky I looked into this a little further because I wanted to know a little more about what was going on. I looked up the Megacrop feeding info, at 6g/gal the levels of Ca and N actually work out to be roughly equivalent to using Prescription Blend at the week 3-4 veg mix, the Mg level in Prescription Blend is slightly higher and these ratios hold as the concentration varies. If your feeding the other killer kush at about 6g/gal then the two are getting about the same level of Ca/N and that would point to this phenotype being a heavy feeder or some other complicating factor. Very interested to see what happens here.
 
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Waira

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As far as mixing order and this goes for any brand, the most important thing is to mix silica supplements first! Silicates in high enough concentration will polymerize to an insoluble form when combine with ionic compounds in solution and especially positively charged metals like Ca2+ and Mg2+. Mixing silica into your water first dilutes the silicates to a point that the polymerization is no longer possible. You can see this effect if you mix a silica after the main nutrients by noticing the little cloudyness that appears where you pour in the silica supplement.
:greenthumb:that's an interesting tip PB, I've not heard this before.. very annoying that other Si brands make no mention of this as it's just a bit relevant if it's locking up vital cations! Can you expand on this more, particularly the polymerization aspects? I've been pummeled enough by chemistry to follow most likely- :rofl:
I was digging around a bit on rice hull Si,.. is it the post burn product, a (soluble) form of SiO2? Another organic mechanic has mentioned using Horsetail to make an Si loaded extract from it... I'm curious to know what form(s) it's takes in the plant...
Some people like it a little higher and Bio-Si could be used to bring it up.
...do you recommend pre-diluting it some in plain water before adding it into a nute solution to avoid that possible cross reaction?
 

Waira

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:pighug: EoF! ... You're like Beetlejuice, I say "organic mechanic" 3 times and you appear outta nowhere! :rofl: Was it you that mentioned Horsetail Si teas?
Yup mate, new company here for some nice test runs! I really like what I see (check their site), and they way the program is broken up... with 6 parts, you can tinker and adjust if needed- :thumbsup: .... I'm planning on trying it this season for tent auto's, and likely the OD photo's harem! :dancer:
 

Bigg Al

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Yes, this one does seem to want a little more then the others. Is this strain a heavy feeder? I ask because it almost looks like it needs an overall higher strength nutrient. What week on the chart were you using when you mixed?

I am going to post a link to a video that one of our customers made about the way he mixes nutrients, he says in the comments that he does chose to add a little cal/mg every other week or so. We will be adding info about this and other specifics on our website, what to watch for etc. and will end up adding a cal/mg product for those people that find they need the extra.

Ill go back and add this to the original thread where we were talking about mixing, this is only one example and not everyone does things the same way.
That water source, is it tap water and is there a water softener in it? I ask cause my tap water ph is that high and I use a water softener. Would that effect (the softener)the nutrient levels? Can I still use my tap?

Thanks
 

Waira

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That water source, is it tap water and is there a water softener in it? I ask cause my tap water ph is that high and I use a water softener. Would that effect (the softener)the nutrient levels? Can I still use my tap?

Thanks
:nono: whoa Al! Is it an ion exchange type, as in the ones that use a crazy strong saline solution to "recharge" the exchange beads? If so, I strongly advise not using it,... the problem is when the mineral ions bind to the beads, they displace a weaker ion off of them, Na or K depending on what salt they use (if it's a service deal) or yourself... Na is toxic at low levels, seen soft water kill many plants at peoples homes and they thought it was their brown thumbs causing it! For K, that's not an issue, but with all the inputs of K from the nutes, there's definite potential for antagonistic and/or toxic effects,...
Have you measured the ppm of your tap?... ion exchange doesn't lower the ppm, it's just pulling out the CaCO3 mainly,....
 

Prescription Blend

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@Bigg Al, Waira is correct here and that there are several kinds of systems and it depends on the counter ion that is used to exchange for carbonate hardness. Bottom line is that it sounds like you have been doing this for a while so if it has been working for you... then it works, not much else to say. If you look at the system you use/the softener you should be able to tell what the counter ion is. The only thing I have to add is that while Waira is correct that ion exchange will not lower the Total disolved solids as the exchange is based on electronic charge but it could read differently on your PPM meter because this measures conductivity and infers a TDS measurement. Different types of ions in solution with identical charge will read differently due to molecular interactions that shield the electronic charge, this is related to the "salt index".


As far as the video, I can't say for sure if they use a softener but I assume its tap water. You could ask the video poster by using the comment section on his video, I know that Bill likes to share info and help fellow growers so my guess it that you'll get a response.
 
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Prescription Blend

Prescription Blend Plant Food for Medical Gardens
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@Waira I would LOVE to elaborate! (now I get to talk about solution chemistry and geology related to growing weed :muahaha:)

You are correct on the post burn of the rice hulls.. the first step is to get rid of the organic matter but this unfortunately does not give a soluble SiO2. I put a pic of the reaction diagram for silica polymerization, the full peer reviewed article can be found here for reference https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3334419/

I have drawn in the colors to make it easier to talk about the process.

In step 1 (red) you see a reversible equilibrium reaction of H2O + Si(OH)4 <->(H3O+) + Si(OH)3O-, where ortho silicic acid (OSA) donates a proton (H+) to a water molecule producing hydronium ion (H3O+) which is an acid, and the conjugate base form of OSA (Si(OH)3O-).

In step 2 (blue) you see a reaction where the negatively charged oxygen forms a bond to the central Si atom of another molecule of OSA while at the same time, one of the OH groups on the second OSA molecule breaks its bond to Si and pulls the proton away from H3O+ making 2 molecules of H2O. This last reaction is OH- + H3O+ -> 2H2O. At the end of step 2 you have a dimer form of silica and you can imagine how it goes from there.

I circled the hydronium ion #3 in purple because this is an extremely important part of the system. At a high pH the concentration of the acidic hydronium is kept very low which prevents this polymerization in concentrated silica supplements!!! Once the silica is mixed into your feedwater and diluted this reaction does not take place because the low concentration provides enough physical separation that they don't contact each other often enough.
Silica polyimerization reaction.jpg


From the same paper directly below figure 2, "Many factors affect the process of silica condensation from the molecular level upwards including concentration, temperature, pressure, pH and the presence of other ions, small molecules and polymers [1 and many subsequent reviews, including 2, 7] but in all cases the materials that form are amorphous on the 1nm length scale and are built up from SiO4 tetrahedra with variable Si-O-Si bond angles and Si-O bond distances. The materials contain hydroxyl groups (some will be present as Si-O-) and according to the reaction environment in which the mineral forms, silica from different organisms/ precipitation conditions can vary greatly with regard to density, hardness, solubility and composition [8]. "

Now for a real world example, NOTE: this is why you never want to mix concentrated nutrients!!

I took ~3ml of Core A and diluted it to ~30ml with tap water and then added a few drops of Bio-Si. These pics were taken over a total 5 min period so you can see this is a fairly fast process. When exposed to the lower pH and Mg2+ the silica almost immediately polymerized forming a white gelatinous blob. I poured out the liquid and refilled the cup with water. As you can see this silica does not re-dissolve and has been taken out of your nutrient solution (literally).

IMG_3758.jpg

IMG_3764.jpg
IMG_3769.jpg
IMG_3771.JPG
IMG_3775.JPG


This is why you should always add silica supplements to your reservoir first and make sure they are thoroughly mixed before adding other nutrients. When topping off a reservoir that already has nutrient solution its best to add your silica to some plain water before putting it in so it is pre-diluted and less likely to react.
 
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Waira

Growing strange,...
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:vibe:OK, time to dust off my chemistry reaction brain cells! :goauto:

So in soln., OSA is playing hot potato proton with a water molecule and (temporarily) forming the conjugate base OSA-
-- when that partly naked O- is hanging out there, it can hook up to the core Si of another OSA ... To do that, it boots an OH- off the Si, easy enough with the unstable H30+ malingering about looking to ditch that extra H+ --> boom! 2 water molecules... (mmm, stoichiometry -:rofl: how many decades since I said that?)
-- from there, the same rxn goes down to form a 3 Si chain molecule, which then in turn decides a cyclic form is the better thermodynamic configuration? I see how the ring is forming there,... no funny bizz with isomers going on, bouncing between chain and cyclic forms?

-- what goes on downstream with the cyclic molecule? Does it tack on more OSA units, and/or 3 Si-O cyclic units (name of that?) ... I gather that's what this is about -->
From the same paper directly below figure 2, "Many factors affect the process of silica condensation from the molecular level upwards including concentration, temperature, pressure, pH and the presence of other ions, small molecules and polymers [1 and many subsequent reviews, including 2, 7] but in all cases the materials that form are amorphous on the 1nm length scale and are built up from SiO4 tetrahedra with variable Si-O-Si bond angles and Si-O bond distances. The materials contain hydroxyl groups (some will be present as Si-O-) and according to the reaction environment in which the mineral forms, silica from different organisms/ precipitation conditions can vary greatly with regard to density, hardness, solubility and composition [8]. "
--roger that on the "cock blocking" of the H3O+ formation under basic pH! :rofl:


Now for a real world example, NOTE: this is why you never want to mix concentrated nutrients!!

I took ~3ml of Core A and diluted it to ~30ml with tap water and then added a few drops of Bio-Si. These pics were taken over a total 5 min period so you can see this is a fairly fast process. When exposed to the lower pH and Mg2+ the silica almost immediately polymerized forming a white gelatinous blob. I poured out the liquid and refilled the cup with water. As you can see this silica does not re-dissolve and has been taken out of your nutrient solution (literally).
:nono: - Oh,... that's nast-eh! --
nast-eh.gif
:haha: ............... how's the Mg++ getting in on this act, as a catalyst or a product?


:cheers: Thanks for that mental exercise PB, this is deeper dot-connecting I crave!
 
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