If you have chemistry questions....

  • Thread starter squiggly
  • Start date
  • Tagged users None
azmmjadvocates

azmmjadvocates

442
43
As i understand it, what you say is only actually relevant for Calcium and Boron which are passively taken up by root tips with water, all other nutrients are actively removed from the rhizosphere independent of the rate of water absorption/transpiration.

Also VPD in horticulture refers to Vapour Pressure Deficit specifically, not differential. Essentially both mean the same thing, just ones technically correct and the others not.

Higher EC needs will be necessary as PPFD (up to ~1500ppfd), CO2 levels (up to ~1200ppm) and/or temperature increases (up to ~89F), less so as VPD optimizes(~0.8-1.2 kPa).

This Is a debate id love to see but hate to convolute and sidetrack Squiggleys awesome thread on Chemistry. I don't look at VPD charts, I look at my $350.00 electric bill for a 3000 sq ft home (24 plants me and wife) in Arizona with a pool mind you. As well as me paying much less for nutes because i'm able to run it real real lean, not that I pay much for nutes anyway lol.

I also believe as Fatman stated previously that VPD charts were created for high water content plants like Tomatoes and have little bearing on cannabis. That isn't saying what everyone else is doing doesn't work for then, I just will keep pointing out how versatile this plant is.

Like I said I'd love to hash all this out in another thread, peaceful of course, and I have an open mind. But my electric bill will play a part in my decision.
 
azmmjadvocates

azmmjadvocates

442
43
First I must say Squiggly I thought you were a smart guy before, but man hats off to you, brother wherever you land after school, you will be doing great, thanks for your input and challenging my thinking as well.

I dont think that is a hard sell just like differing ph effects on differing nutrients. The question is like with PH the range in which those temp fluctuations have relatively little impact, Fatman's argument of Rez temps come to mind relating to DO, there are many people such as myself who are happy with their results and do things in opposition to the NORM. There is so much not in just chemistry but relating to plant physics (like remove the root cap that controls gravity and roots dont know up from down) and new discoveries in plant biology with new funny names, that is just getting discovered that may have contradictory roles to play as well that originate a lot of times from a slice of science or ganja gurus methodology as opposed to the holistic science of chemistry, biology and plant physics, such as research on how plants react to touch, other plants, and gravity.


Sorry ran out of time to edit: When I was referring to Fatmans DO, it was how he runs such high rez temps successfully and that to get a real significant DO increase into a solution, the rez temp would need to be at such a low temp it would not be practical with the plants biology. So basically my comment doesn't have to do with DO but rather the temp ranges he was discussing. It's, what is an acceptable range u are suggesting, of course recirculating vs DTW ect. temps have a roll to play, I do give that as an example.
 
dizzlekush

dizzlekush

62
18
This Is a debate id love to see but hate to convolute and sidetrack Squiggleys awesome thread on Chemistry. I don't look at VPD charts, I look at my $350.00 electric bill for a 3000 sq ft home (24 plants me and wife) in Arizona with a pool mind you. As well as me paying much less for nutes because i'm able to run it real real lean, not that I pay much for nutes anyway lol.

I also believe as Fatman stated previously that VPD charts were created for high water content plants like Tomatoes and have little bearing on cannabis. That isn't saying what everyone else is doing doesn't work for then, I just will keep pointing out how versatile this plant is.

Like I said I'd love to hash all this out in another thread, peaceful of course, and I have an open mind. But my electric bill will play a part in my decision.
If you can find a place where Fatty hasn't been banned, id love to have the discussion with him. Ive actually wanted to discuss with him for some time now why his opinion on VPD is so... flying in the face of 30+ years of science establishing the factors of stomatal conductance, the photosynthesis-transipiration dilemma, the fact that transpiration efficiency is genetically determined (we're even finding out which genes such as ERECTA and GPA1), etc., etc. Theres absolutely nothing ive seen that compliments his theory that increased transpiration = increased growth. It seems like an oversimplified concept of 'this is how i force more into the plant'.

His theory that cranking transpiration to the max like he does with 80+ temps and ~40% humidity (giving you at the very least >2.0kPa), while using 150w bulbs (low irradiance) wont drastically reduce stomatal conductance and therefore photosynthetic net just doesn't make any sense to me.... doesn't matter if your plants are getting more DO... This study didn't even find any quantifiable difference between hydroponic plants grown in 2.1 and 16.8ppm DO water:
http://www.ncbi.nlm.nih.gov/pubmed/11541573

The only way you get >16.8 ppm is in rare setups like HP Aero, fogging units or possibly a venturi infused RDWC unit, which i've never even seen.

Maybe im missing something?

Im also gonna guess you're a fan of Fatty. If so, be warned. Out of the limited number of very intelligent growers that visit cannabis forums with a good forte in some aspect of the broad science of horticulture, Fatty seems to have the biggest chip on his shoulder and the most incorrect info. Im fairly sure he's wrong on the subject of VPD, and i know he's wrong in suggesting 1500ppm CO2, Rubisco Activase will definitely be inhibited at those levels(or any levels >1200ppm), also ethylene buildup starts becoming a significant factor. Also his suggesting of the 3-1-2 ration all the way through growth & bloom is, to say the least, in-optimal. Im sure there's more of his suggestions that i could pick at, i just have forgotten most of what the man has said that didnt have specifically to do with his particular forte, the nitty-gritty's of aeroponics, which is the only subject where his credibility seems high enough to usually not question.

Lets discuss this no further on this particular thread, as to not hijack squiggly's awesome thread, unless s/he shows an interest in discussing it as well.
 
rick ratlin

rick ratlin

Perpetual Farmer
Supporter
309
93
Hey Squiggly, I've been trying to resolve a few issues in my room. I think I've got it pinned on a bad batch of 50% H2O2. It has always been food grade, but I believe its not. I think it has stabilizers in it, which I've heard can cause problems. I dose at 1 ml/L with a sterile tank of Dyna Gro nutes. After a day, the mix is cloudy. How can I find out, or what questions should I ask the supplier to find out?
 
squiggly

squiggly

3,277
263
Peroxides can be unstable at times (this is why they're so reactive and good for the purpose of killing stuff that is alive)--it's possible it went bad. Can't think of any easy way to test it unless you had some chemical reagents just lying around.

A possible situation:

You H2O2 is oxidizing a chemical present in your nutes--and this is causing it to precipitate out. Likewise it could be something in your water (unless you're running RO/DI).

Other than that I'm not sure. I need more information.
 
squiggly

squiggly

3,277
263
Lets discuss this no further on this particular thread, as to not hijack squiggly's awesome thread, unless s/he shows an interest in discussing it as well.

If it's science-related, feel free. I'll jump in if something is bothering me or I have something to add. (I'll add my own schpiel on this later)
 
pork

pork

197
28
finding that my calcium nitrate is flocculating out when i'm adding it to my res after adding Jack's MOST, and MgSO4 (along with KSO4, and MKP)...basically getting a cloudy res after a couple minutes of mixing..tried various things, currently i'm:

mixing calnit in 1 gal warm water before putting in tank (after waiting a hour or so)
happens whether i use light airstone bubbling in the tank or super heavy....

ideas?
 
squiggly

squiggly

3,277
263
finding that my calcium nitrate is flocculating out when i'm adding it to my res after adding Jack's MOST, and MgSO4 (along with KSO4, and MKP)...basically getting a cloudy res after a couple minutes of mixing..tried various things, currently i'm:

mixing calnit in 1 gal warm water before putting in tank (after waiting a hour or so)
happens whether i use light airstone bubbling in the tank or super heavy....

ideas?

Can you get me a run down of all of the salts in your solution?

If that isn't available it will be difficult to make a judgement.

Most likely you're just doing a simple precipitation.

Take a look at this chart:



(the "groups" refer to groups in the periodic table which you may refer to).


If I had my guess I'd say you're precipitating out "something"SO4--usually the most likely culprit, though silicates are known to be dickheads as well.


You can try bringing the pH way down while mixing and then adjusting to a good level afterwards--and also coming from the opposite direction by trying with a high pH.

If you still get clouding after that--you are definitely doing a simple precipitation and something in your nute regimen needs to be removed.
 
azmmjadvocates

azmmjadvocates

442
43
If you can find a place where Fatty hasn't been banned, id love to have the discussion with him. Ive actually wanted to discuss with him for some time now why his opinion on VPD is so... flying in the face of 30+ years of science establishing the factors of stomatal conductance, the photosynthesis-transipiration dilemma, the fact that transpiration efficiency is genetically determined (we're even finding out which genes such as ERECTA and GPA1), etc., etc. Theres absolutely nothing ive seen that compliments his theory that increased transpiration = increased growth. It seems like an oversimplified concept of 'this is how i force more into the plant'.

His theory that cranking transpiration to the max like he does with 80+ temps and ~40% humidity (giving you at the very least >2.0kPa), while using 150w bulbs (low irradiance) wont drastically reduce stomatal conductance and therefore photosynthetic net just doesn't make any sense to me.... doesn't matter if your plants are getting more DO... This study didn't even find any quantifiable difference between hydroponic plants grown in 2.1 and 16.8ppm DO water:
http://www.ncbi.nlm.nih.gov/pubmed/11541573

The only way you get >16.8 ppm is in rare setups like HP Aero, fogging units or possibly a venturi infused RDWC unit, which i've never even seen.

Maybe im missing something?

Im also gonna guess you're a fan of Fatty. If so, be warned. Out of the limited number of very intelligent growers that visit cannabis forums with a good forte in some aspect of the broad science of horticulture, Fatty seems to have the biggest chip on his shoulder and the most incorrect info. Im fairly sure he's wrong on the subject of VPD, and i know he's wrong in suggesting 1500ppm CO2, Rubisco Activase will definitely be inhibited at those levels(or any levels >1200ppm), also ethylene buildup starts becoming a significant factor. Also his suggesting of the 3-1-2 ration all the way through growth & bloom is, to say the least, in-optimal. Im sure there's more of his suggestions that i could pick at, i just have forgotten most of what the man has said that didnt have specifically to do with his particular forte, the nitty-gritty's of aeroponics, which is the only subject where his credibility seems high enough to usually not question.

Lets discuss this no further on this particular thread, as to not hijack squiggly's awesome thread, unless s/he shows an interest in discussing it as well.

Sincerely, thank's for your response, Thanks squiggly for offering the debate here in the name of science, however it's been on my mind for some time and I think this would be better on a dedicated thread to his theories as well, albeit Fatman postmortem..

Give me a couple days to get things compiled, I'll post the meat and potatoes of his "theories" i've compiled from here and different forums (fair use) for those who wish to pick them apart and hopefully cite links to scientific research that contradicts his theories. In the name of science and education, I'll certainly keep an open mind as I do research against those contradictions. Perhaps we can make headway twards or away from fatmans theories without fatmans buttons getting pushed and him subsequently silenced.

Like I stated before, I can't argue with my electric bill, I didn't remember him using 150wt and I don't use 200 wt 2" from plants like fatman, but rather 600 dialed down at times to 400, perhaps some of what he does is for other reasons as some might think. As for the DO I mentioned that thread based upon squiggles temp and wasn't referring to the DO part, however fatman was basically stating the DO plants uptake in solution cant be increased drastically as people think, if I gather right that is about what u just said.

I can't argue with the knowledge he has shared with nutes, i'm certainly happy with my results. In Arizona as you can imagine it gets quite hot in the summer, so instead of fight it , I roll with it and have great success despite not looking at any VPD charts, not having any mold in my house is a nice bonus too.

I'll start one and post a link here, I'd like to hear what everyone has to say in a postmortem pissing match lol, and hopefully nobody will get banned, who knows maby Fatman will one day resurrect and comment back. Hell maby he should just pm someone responses? I know he has friends here, that would be cool, he wouldn't get banned that way.
 
azmmjadvocates

azmmjadvocates

442
43
Peroxides can be unstable at times (this is why they're so reactive and good for the purpose of killing stuff that is alive)--it's possible it went bad. Can't think of any easy way to test it unless you had some chemical reagents just lying around.

A possible situation:

You H2O2 is oxidizing a chemical present in your nutes--and this is causing it to precipitate out. Likewise it could be something in your water (unless you're running RO/DI).

Other than that I'm not sure. I need more information.
I like using it to clean my tank between changes, you can see it smoke sometimes as it hits the walls that appear clean, then you see the organics you thought you didn't have slide down in their death throws lol.. Could it be the tank wasn't totally sterile? Ive tested mine by by diluting to 3% and pouring it on some blood or the dog piss on the carpet lol.. Pretty good test for me, not to scientific though lol.

On a side question, those fillers people worry about in the 3% I've heard it's BS, it's not there in the Brown bottle at least, just distilled water and 3% h202 which is what is stated on the label. with that said I called the company and nobody returned my call, perhaps I should pretend to be the hospital calling needing the ingredients from a poisoning lol,, Kidding of course. Looking at the label it states active ingredient H2O2 inactive distilled water. I know people in AG use it straight out the 3 % , .88 cent bottle. It's more cost effective for me though to get the 29% but im in a city, so what do you think? just a marketing ploy can you test it for us?.
 
ttystikk

ttystikk

6,892
313
As i understand it, what you say is only actually relevant for Calcium and Boron which are passively taken up by root tips with water, all other nutrients are actively removed from the rhizosphere independent of the rate of water absorption/transpiration.

Also VPD in horticulture refers to Vapour Pressure Deficit specifically, not differential. Essentially both mean the same thing, just ones technically correct and the others not.

Higher EC needs will be necessary as PPFD (up to ~1500ppfd), CO2 levels (up to ~1200ppm) and/or temperature increases (up to ~89F), less so as VPD optimizes(~0.8-1.2 kPa).

This is fascinating stuff- you've pointed out an assumption I made, apparently incorrectly; that increasing EC was directly related to RH/VPD considerations. Since I increase my RH at the same time as light levels, CO2 and temperatures, I see where I made the mistake. Does this mean that I should only add additional calcium and boron, or do I need to add more of everything when running a higher intensity garden?

This Is a debate id love to see but hate to convolute and sidetrack Squiggleys awesome thread on Chemistry. I don't look at VPD charts, I look at my $350.00 electric bill for a 3000 sq ft home (24 plants me and wife) in Arizona with a pool mind you. As well as me paying much less for nutes because i'm able to run it real real lean, not that I pay much for nutes anyway lol.

I also believe as Fatman stated previously that VPD charts were created for high water content plants like Tomatoes and have little bearing on cannabis. That isn't saying what everyone else is doing doesn't work for then, I just will keep pointing out how versatile this plant is.

Like I said I'd love to hash all this out in another thread, peaceful of course, and I have an open mind. But my electric bill will play a part in my decision.

I'm discussing the effects of chemicals and the levels at which they're applied to plants. This is a chemistry questions related to growing thread. If it's not relevant here, perhaps you could tell me what is?!
 
dizzlekush

dizzlekush

62
18
If it's science-related, feel free. I'll jump in if something is bothering me or I have something to add. (I'll add my own schpiel on this later)
Thanks, and looking forward to hearing your spiel on the subject.

I think this would be better on a dedicated thread to his theories as well, albeit Fatman postmortem. Give me a couple days to get things compiled, I'll post the meat and potatoes of his "theories" i've compiled from here and different forums (fair use) for those who wish to pick them apart and hopefully cite links to scientific research that contradicts his theories.. Perhaps we can make headway twards or away from fatmans theories without fatmans buttons getting pushed and him subsequently silenced.

Like I stated before, I can't argue with my electric bill, I didn't remember him using 150wt and I don't use 200 wt 2" from plants like fatman,

I'll start one and post a link here, I'd like to hear what everyone has to say in a postmortem pissing match.
Id be interesting in seeing a good compilation of Fattys work. The fact that he got banned almost as soon as he started posting on any forum made it difficult to find his stuff.

My mistake on the 150w bulbs, i just remember that they were very low intensity. So he uses 200w at 2" from the canopy top? that sounds kinda ridiculous to me, you cant even get an even spread across ONE plant with that, let alone have an evenly lit canopy, not to mention the ridiculous amount of lighting units you'd have to put in... also that'll crank up leaf surface temp well above 78F (again not good, different from optimal room temps)... I hope he doesn't suggest anyone to light their rooms in a similar fashion.

This is fascinating stuff- you've pointed out an assumption I made, apparently incorrectly; that increasing EC was directly related to RH/VPD considerations. Since I increase my RH at the same time as light levels, CO2 and temperatures, I see where I made the mistake. Does this mean that I should only add additional calcium and boron, or do I need to add more of everything when running a higher intensity garden?

The rate at which your plant removes water, Ca, and B from the nutrient solution is dependent on the rate of transpiration, which is dependent on VPD, so the greater the VPD, the greater the plant uptakes water, Ca and B. Good root structure (high total surface area of root hair tips) is more important for Ca and B uptake than all other nutrients as well. Ca and B are also immobile (along with Fe and S) so they need to be constantly available otherwise new growth will quickly become stunted & nutrient deficient.

Your plant removes all other nutrients (including Fe and S, but not Ca and B) dependent on the rate of growth, so the faster the growth the more all other nutrients have to be applied. Meaning an increase in any factor that will increase growth (irradiance, temperature, CO2, plant growth stimulants) demands an increase for all other nutrients.

So if you have high temps and low humidity (high VPD) than you should be feeding a relatively lower EC solution than if you had greater humidity (lower VPD) since your plants water requirements have increased from the high VPD while requirements for other nutrients has stayed the same (or possibly even decreased due to slowed growth rates from reduced stomatal conductance from the high VPD, therefore reducing carbon fixation and photosynthetic net).
 
pork

pork

197
28
Can you get me a run down of all of the salts in your solution?

If that isn't available it will be difficult to make a judgement.

Most likely you're just doing a simple precipitation.

Take a look at this chart:



(the "groups" refer to groups in the periodic table which you may refer to).


If I had my guess I'd say you're precipitating out "something"SO4--usually the most likely culprit, though silicates are known to be dickheads as well.


You can try bringing the pH way down while mixing and then adjusting to a good level afterwards--and also coming from the opposite direction by trying with a high pH.

If you still get clouding after that--you are definitely doing a simple precipitation and something in your nute regimen needs to be removed.


mixing Pro-Tekt at 2 mL/gal
Then MKP, KSO4, and MgSO4
Then Ca(NO3)2

final ratio 120-90-300-150-75-177(ish..notes not beside me right now)

I have been thinking that its Ca and SO4 that are not liking each other too much..but how is it that premixed ferts cause no problem and me doing it does? im using well water going through a tallboy water filter...was thinking that it was too high SO4, so i redid my mix with some K NItrate and it still happened... Maybe mix the CalNit first and let it stew for a while?
 
squiggly

squiggly

3,277
263
mixing Pro-Tekt at 2 mL/gal
Then MKP, KSO4, and MgSO4
Then Ca(NO3)2

final ratio 120-90-300-150-75-177(ish..notes not beside me right now)

I have been thinking that its Ca and SO4 that are not liking each other too much..but how is it that premixed ferts cause no problem and me doing it does?


It's probably the Silica, actually--now that I see you're adding it.

Try cutting it out and get back to me with results. Did you try doing the pH trick I suggested?


Sometimes things can be partially soluble--and even those things which are completely soluble have limits (i.e. the solvent can run out of "spaces" for solutes). To convince yourself of this you may add salt to boiling water until no more will dissolve, and then cool the mixture. You can watch salt precipitate out as it cools.

When something is partially soluble it does much the same thing, but its subject to more effects than heat and solvent strength when there is a potential for new salts to be created. Certain salts will have a preference toward precipitating out more readily, and in lower concentrations, than others.

A good example again is comparing table salt (or any sodium salt, really) with something like a lead salt.

The lead salt is going to be almost completely insoluble--but it does have a very tiny solubility product, so maybe 0.01mg/L will dissolve. The short answer as to why this doesn't happen with other brands is that they've tested their mixture to ensure that it doesn't.

They more than likely went through troubles like this one when formulating it--but testing weeds problem like this out.
 
dizzlekush

dizzlekush

62
18
can I mix the calcium chloride and mgso4 to the calcium nitrate side (A ) without any reactions?. and can I add the MOST and MKP in with the B side hydro? If not is there a way I can make a 3 part? or do I have to keep doing it hoagland style and mixing in individual bottles? That would still save me time because the hydro would be only one bottle. so that would be like a 5 part. Thanks for your time
I see your Q got skipped.

CaCl2 and Calcinit can be mixed together, they often are in Cal/Mag products (MagiCal for example) but neither of them can be mixed with MgSO4, the Ca and S will react and precipitate out of solution.

The MKP can be added to the Jacks Pro hydro directly, its the most abundant salt in Jacks Pro already, the MOST has such a high amount of S in it that id be cautious of mixing it in a concentrated amount with anything really besides the MgSO4, but see if squiggly has anything to add.

So I guess you could do:

Part A:
Jacks Pro Hydro
MKP

Part B:
CalciNit
CaCl2

Part C:
MgSO4
MOST

MOST is really unnecessary if you already have the Jacks Pro Hydro, although the micronutrient package in Jacks could use more Zn IMO, so buying a little Zinc sulfate or Zinc EDTA makes more sense if you want to use the Jacks. The CaCl2 is also very unnecessary, blooming cannabis loves lots of NO3, despite the popular belief that it doesn't. N demands will always be more than Ca demands. If the plant will ever want the Ca, it will want the NO3 that comes with it in CalciNit. Also Ca accumulates both in soil and hydroponic solutions more than any other nutrient, and too much Ca can really delay maturation (another very little known fact) so application rates for Ca should decrease over time.

P.S. You really don't want to be ADDING any chloride to your mix, unless you're using RO water and reagent grade salts i can almost guarantee your plant is already getting way more chloride than it wants without adding any. The only reason i can see to expose your plant to the additional chloride is if you want to use the CaCl2 as a foliar spray, since CaCl2 has the lowest point of dilequescence out of all Ca salts (at ~32% RH), giving it the greatest efficacy of all Ca salts when it comes to foliar applications. It also has some fungicidal effects.
 
pork

pork

197
28
wi
mixing Pro-Tekt at 2 mL/gal
Then MKP, KSO4, and MgSO4
Then Ca(NO3)2

final ratio 120-90-300-150-75-177(ish..notes not beside me right now)

I have been thinking that its Ca and SO4 that are not liking each other too much..but how is it that premixed ferts cause no problem and me doing it does? im using well water going through a tallboy water filter...was thinking that it was too high SO4, so i redid my mix with some K NItrate and it still happened... Maybe mix the CalNit first and let it stew for a while?


i'll drop the protekt and see what happens...also how low of pH should i start with for the pH trick? it's funny, the res will could up whether i add the CalNit first or last..
 
ttystikk

ttystikk

6,892
313
For what it's worth, I use Pro-Tekt silica in veg and early bloom at the rate of 1ml.gallon, and it works fine. Just put it in first.

When using Jacks, as long as you have a reasonably large water volume you're mixing into (at least a gallon if you're mixing up to 50 gallons of nutes), you can add the epsom salts to the Jacks bucket and it won't flocculate. The important thing is to keep the sulphur and calcium apart until they see the res. at diluted strength, because they like to play together and make gypsum. Good for wallboard and organics, not so much for hydro.
 
pork

pork

197
28
leaving the protekt out didn't have an affect on the precipitation...started with pH at 5.7 before adding anything to the tank..CalNit first...hour later MKP, KSulf, and Epsom...

i would really love to figure this out...cause the cloudy res makes me worry...
 
squiggly

squiggly

3,277
263
Then its almost assuredly the Sulfur thats giving you an issue. What might be hurting you is that you're adding potassium sulfate AND magnesium sulfate(epsom)--cut one of those out.
 
squiggly

squiggly

3,277
263
Also, for the pH trick I suggested you want to take the pH pretty low--say 4 (or as high as 9.5-10 if you're coming from the other direction).
 

Latest posts

Top Bottom