ShedsAndTents
Active Member
So I'm creating this to reduce my redundancy.
Consider this as my reference thread so I don't have to type the same stuff over and over again, I understand it can be cumbersome to search through threads endlessly only to find partial, inconsistent and often plain false information. I was considering the advanced thread section but considering this isn't a technique I didn't seem a valid action. Also, I believe this should be common knowledge and not the result of years of research. I mean, this millennia is all about instant gratification right?
If you aren't a reader and want some straight facts I will post a summary at the end of the post.
If you can site sources with contradicting, updating or even additional information all updates will be reflected to this initial post so no specific page searching is necessary.
PPM
1st. What is EC?
It's a measure of ELECTRICAL CONDUCTIVITY in a solution. Not "Total Dissolved Solids" as it is generally sold, spread and thought.
Think Total dissolved salts instead.
Water with a ppm of 0PPM could effectively negate electrical conductivity if it hasn't absorbed the carbon from the air creating carbonic acid.
Also! If a source of fertilizer isn't electrically conductive, it won't register on a EC/PPM reading. Organic growers have long touted the lack of importance to check feed ppms. I think knowing everything you can is what's truly important.
2nd. Why and how it affects feedings.
I'm sure you have heard of tip burn right? Maybe we should start calling it Tip drying? Nah.. Tip burn is fine.
"Tip burn is the result of high ppm" I'm very sure you've heard that one. Why is this? Your plant has an EC measurement of it's own, after storing so many it will rise. Which is why we raise the EC or PPM's of a feeding. When we raise the electrical conductivity of a solution, that solution has a higher pressure.
P(osm) = 1.19 (T + 273) *Σ(mi) (1)
where P(osm)= osmotic pressure (in psi),
T is the temperature (in°C),
and Σ(mi) is the sum of molal concentration of all constituents in a solution.
An approximation for P(osm) may be made by assuming that 1000 ppm of Total Dissolved Salts
(TDS) equals about 11 psi (0.76 bar) of osmotic pressure.
As we know osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.
Low(er) ppm high water [Soil] -> High(er) ppm (concentration) Low water [Plant cells]
Think 1L with 1000ppm(Soil) -> 1mL @ 100ppm (Plant Cell)
The 1L may have more ppm but the 1mL is more concentrated.
[1mL @ 100ppm x 1000 = 1L @ 100,000 ppms]
Kind of sounds like underfeeding might be more dangerous but infact the Plant cells have a higher concentration of salts due to relative concentrations.
P(osm)
The pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis, often used to express the concentration of the solution -
the PPM in leaf tissues are actually taking up the lower concentrations except when the osmotic pressure is too high (High PPM) this is when the Atmospheric pressure further affects translocation of our nutrients. If you have an atmospheric pressure that exceeds osmotic pressure the plant will not uptake nutrients because the lack of transpiration.
The lower the Humidity (Low Atmospheric Pressure) the more negative pressure (Pulling from leaves -> atmosphere) the higher the PPMs in the feeding solution before osmotic pressure results in creating a "Reverse Osmosis"
Sum up -
High soil moisture->Positive pressure(Soil->Roots->Leaves->Atmosphere) {Wet vs dry soil}
Osmotic pressure->Negative pressure(<water + >PPM {Feed solution} -> >Water + <PPM {Plant cells})
Atmospheric pressure->Dynamic pressure(Higher -> Lower Pressures {regulated by stomata})
Now what does this equate to theoretically?
If you feed your plants higher ppm than inside the cells, and the soil moisture is low, and the pressure in the atmosphere isn't pulling hard enough on the stomata (When it is too high of humidity[High AP]) The water will actually pull from the leaves back into xylem and eventually sit where it finds equilibrium (The goal of all pressures)
TIP BURN
If you feed your plants higher ppm than inside the cells (remember the cell walls AND Feed solution have osmotic pressure of their own) and the soil moisture is high (high root pressure), and the atmospheric pressure is high then the water will move according to hydro-static pressure (Water levels are at equillibrium and is affected mostly by gravity) causing pressure in the cell walls, but a lack of transpiration. Think of a glass half full and your straw only reaches 1cm into the cup.
WRINKLY AND BLOATED LEAVES
If you feed your plants a higher ppm solution than inside the cells, the soil moisture is high and the atmosphere is pulling the water from the stomata (Low AP) than transpiration is possible but more water than nutrients are taken up. Your straw now reaches as far as the waters equilibrium by gravity and the root pressure keeps your straw supplied.
If you feed your plants a lower ppm than inside the cells, the soil moisture is high and atmospheric pressure is low, Plants can transpire and effectively translocate ions because it's not fighting the atmosphere to equate turgor pressure .
If you feed your plants a lower ppm than inside the cells, the soil moisture is low and atmospheric pressure is low(low humidity less pull) plants will close stomata to reserve water WASTE.
If you feed your plants a lower ppm than inside the cells, the soil moisture is high and atmospheric pressure is high, water will exit stomata slower, as the root pressure isn't as strong as transpiration and both are affected by osmotic pressure (Low ppm high water -> high ppm low water)
If you feed your plants a lower ppm than inside the cell walls, the soil moisture is high and atmospheric pressure is low (Pulling water from the leaves) plants can effectively transpire and translocate Ions.
I hope you get the idea because I lost interest in going through all of them and I feel i have lost a bit of direction.
On a side note, low transpiration rates will cause inadequate calcium translocation because it is immobile and relies on transpiration for movement.
If you are having calcium issues, check your Humidity first, leaf surface temperature second (Low LST causes slower transpiration and enzyme/metabolic activity hence the low temps=Slow growth) and finally try adding calmag. If you would like an alternative, add amino acids from plant protein hydroslate as these initiate enzymes that create Calcium ion channels that can increase calcium uptake exponentially.
High humidity + high temperatures = Leaf temperature overload/Lack of transpirational cooling.
High humidity + low temps = Low metabolic activity lack of transpiration.
Low humidity + high temps = rapid transpiration or closing of stomata high metabolic activity without restoring nutrient reserves
low humidity + low temps = low metabolic activity higher transpiration = nutrients not used optimally.
VPD is your friend here and leaf surface temperatures are happy at 85F+\-
Closer lights = higher LST remedied by lowering ambient temps but reduce soil activity as they aren't getting heated by the lights.
I DIGRESS.
High ppm = Keeping soil moist more often(Make sure you have oxygenated roots) and lowering humidity(Not crazy, but not >65%)
PH
1st. If you thought PPM could be convoluted try this!
You've seen a nice little chart before like this
http://www.growing-life.com/shop/pH_and_Nutrient_Availability_chart.html
Or maybe like this crazy looking one
https://www.growweedeasy.com/wp-content/uploads/2010/05/soil-ph-chart-marijuana.jpg
But did you know that these charts used a specific form of each nutrient.
Phosphoric acid
calcium phosphate
Rock Phosphate
Mono ammonium Phosphate
All these have phosphorus in them but phosphoric acid can bond easily to calcium creating calcium phosphate. 95% water insoluble(Water is our conduit for ion translocation) and is only available as nutrition at a ph >7 on top of that.
Rock Phosphate is available at a ph <5.5 and is commonly used in organic farming. why does it work? The complex chain is broken down by soil microbiology over a long period of time.
MAP is available immediately when diluted in water and the Ammonium and Phosphorus chains break apart providing nitrogen ions and phosphorus ions. Meaning that chart is more than likely accurate when referring to this particular form of P.
This one is easier to sum up.
PH is relative, Indica strains have developed near more neutral/alkaline soil. Sativa is accustomed to acidic soil. does that super matter? No, but I do believe mixing and matching brands of fertilizers cause many unknown problems because your ph is in that range on the chart but you're experiencing deficiencies with only the PH to blame as the nutrients are present.
Companies(Most) have tested their proprietary blend and all of their nutrients are available and released at their "preffered" PH.
If you like a brand, try their whole line up instead of cutting corners because this guys calmag is cheap but homeboys Bloom is affordable. Ask customer service for their PH range, It's kind of funny how we have a wide range of PH preferences and it works for each of us but bash on someone who uses a ph that would "Kill my plants"
Consider this as my reference thread so I don't have to type the same stuff over and over again, I understand it can be cumbersome to search through threads endlessly only to find partial, inconsistent and often plain false information. I was considering the advanced thread section but considering this isn't a technique I didn't seem a valid action. Also, I believe this should be common knowledge and not the result of years of research. I mean, this millennia is all about instant gratification right?
If you aren't a reader and want some straight facts I will post a summary at the end of the post.
If you can site sources with contradicting, updating or even additional information all updates will be reflected to this initial post so no specific page searching is necessary.
PPM
1st. What is EC?
It's a measure of ELECTRICAL CONDUCTIVITY in a solution. Not "Total Dissolved Solids" as it is generally sold, spread and thought.
Think Total dissolved salts instead.
Water with a ppm of 0PPM could effectively negate electrical conductivity if it hasn't absorbed the carbon from the air creating carbonic acid.
Also! If a source of fertilizer isn't electrically conductive, it won't register on a EC/PPM reading. Organic growers have long touted the lack of importance to check feed ppms. I think knowing everything you can is what's truly important.
2nd. Why and how it affects feedings.
I'm sure you have heard of tip burn right? Maybe we should start calling it Tip drying? Nah.. Tip burn is fine.
"Tip burn is the result of high ppm" I'm very sure you've heard that one. Why is this? Your plant has an EC measurement of it's own, after storing so many it will rise. Which is why we raise the EC or PPM's of a feeding. When we raise the electrical conductivity of a solution, that solution has a higher pressure.
P(osm) = 1.19 (T + 273) *Σ(mi) (1)
where P(osm)= osmotic pressure (in psi),
T is the temperature (in°C),
and Σ(mi) is the sum of molal concentration of all constituents in a solution.
An approximation for P(osm) may be made by assuming that 1000 ppm of Total Dissolved Salts
(TDS) equals about 11 psi (0.76 bar) of osmotic pressure.
As we know osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.
Low(er) ppm high water [Soil] -> High(er) ppm (concentration) Low water [Plant cells]
Think 1L with 1000ppm(Soil) -> 1mL @ 100ppm (Plant Cell)
The 1L may have more ppm but the 1mL is more concentrated.
[1mL @ 100ppm x 1000 = 1L @ 100,000 ppms]
Kind of sounds like underfeeding might be more dangerous but infact the Plant cells have a higher concentration of salts due to relative concentrations.
P(osm)
The pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis, often used to express the concentration of the solution -
the PPM in leaf tissues are actually taking up the lower concentrations except when the osmotic pressure is too high (High PPM) this is when the Atmospheric pressure further affects translocation of our nutrients. If you have an atmospheric pressure that exceeds osmotic pressure the plant will not uptake nutrients because the lack of transpiration.
The lower the Humidity (Low Atmospheric Pressure) the more negative pressure (Pulling from leaves -> atmosphere) the higher the PPMs in the feeding solution before osmotic pressure results in creating a "Reverse Osmosis"
Sum up -
High soil moisture->Positive pressure(Soil->Roots->Leaves->Atmosphere) {Wet vs dry soil}
Osmotic pressure->Negative pressure(<water + >PPM {Feed solution} -> >Water + <PPM {Plant cells})
Atmospheric pressure->Dynamic pressure(Higher -> Lower Pressures {regulated by stomata})
Now what does this equate to theoretically?
If you feed your plants higher ppm than inside the cells, and the soil moisture is low, and the pressure in the atmosphere isn't pulling hard enough on the stomata (When it is too high of humidity[High AP]) The water will actually pull from the leaves back into xylem and eventually sit where it finds equilibrium (The goal of all pressures)
TIP BURN
If you feed your plants higher ppm than inside the cells (remember the cell walls AND Feed solution have osmotic pressure of their own) and the soil moisture is high (high root pressure), and the atmospheric pressure is high then the water will move according to hydro-static pressure (Water levels are at equillibrium and is affected mostly by gravity) causing pressure in the cell walls, but a lack of transpiration. Think of a glass half full and your straw only reaches 1cm into the cup.
WRINKLY AND BLOATED LEAVES
If you feed your plants a higher ppm solution than inside the cells, the soil moisture is high and the atmosphere is pulling the water from the stomata (Low AP) than transpiration is possible but more water than nutrients are taken up. Your straw now reaches as far as the waters equilibrium by gravity and the root pressure keeps your straw supplied.
If you feed your plants a lower ppm than inside the cells, the soil moisture is high and atmospheric pressure is low, Plants can transpire and effectively translocate ions because it's not fighting the atmosphere to equate turgor pressure .
If you feed your plants a lower ppm than inside the cells, the soil moisture is low and atmospheric pressure is low(low humidity less pull) plants will close stomata to reserve water WASTE.
If you feed your plants a lower ppm than inside the cells, the soil moisture is high and atmospheric pressure is high, water will exit stomata slower, as the root pressure isn't as strong as transpiration and both are affected by osmotic pressure (Low ppm high water -> high ppm low water)
If you feed your plants a lower ppm than inside the cell walls, the soil moisture is high and atmospheric pressure is low (Pulling water from the leaves) plants can effectively transpire and translocate Ions.
I hope you get the idea because I lost interest in going through all of them and I feel i have lost a bit of direction.
On a side note, low transpiration rates will cause inadequate calcium translocation because it is immobile and relies on transpiration for movement.
If you are having calcium issues, check your Humidity first, leaf surface temperature second (Low LST causes slower transpiration and enzyme/metabolic activity hence the low temps=Slow growth) and finally try adding calmag. If you would like an alternative, add amino acids from plant protein hydroslate as these initiate enzymes that create Calcium ion channels that can increase calcium uptake exponentially.
High humidity + high temperatures = Leaf temperature overload/Lack of transpirational cooling.
High humidity + low temps = Low metabolic activity lack of transpiration.
Low humidity + high temps = rapid transpiration or closing of stomata high metabolic activity without restoring nutrient reserves
low humidity + low temps = low metabolic activity higher transpiration = nutrients not used optimally.
VPD is your friend here and leaf surface temperatures are happy at 85F+\-
Closer lights = higher LST remedied by lowering ambient temps but reduce soil activity as they aren't getting heated by the lights.
I DIGRESS.
High ppm = Keeping soil moist more often(Make sure you have oxygenated roots) and lowering humidity(Not crazy, but not >65%)
PH
1st. If you thought PPM could be convoluted try this!
You've seen a nice little chart before like this
http://www.growing-life.com/shop/pH_and_Nutrient_Availability_chart.html
Or maybe like this crazy looking one
https://www.growweedeasy.com/wp-content/uploads/2010/05/soil-ph-chart-marijuana.jpg
But did you know that these charts used a specific form of each nutrient.
Phosphoric acid
calcium phosphate
Rock Phosphate
Mono ammonium Phosphate
All these have phosphorus in them but phosphoric acid can bond easily to calcium creating calcium phosphate. 95% water insoluble(Water is our conduit for ion translocation) and is only available as nutrition at a ph >7 on top of that.
Rock Phosphate is available at a ph <5.5 and is commonly used in organic farming. why does it work? The complex chain is broken down by soil microbiology over a long period of time.
MAP is available immediately when diluted in water and the Ammonium and Phosphorus chains break apart providing nitrogen ions and phosphorus ions. Meaning that chart is more than likely accurate when referring to this particular form of P.
This one is easier to sum up.
PH is relative, Indica strains have developed near more neutral/alkaline soil. Sativa is accustomed to acidic soil. does that super matter? No, but I do believe mixing and matching brands of fertilizers cause many unknown problems because your ph is in that range on the chart but you're experiencing deficiencies with only the PH to blame as the nutrients are present.
Companies(Most) have tested their proprietary blend and all of their nutrients are available and released at their "preffered" PH.
If you like a brand, try their whole line up instead of cutting corners because this guys calmag is cheap but homeboys Bloom is affordable. Ask customer service for their PH range, It's kind of funny how we have a wide range of PH preferences and it works for each of us but bash on someone who uses a ph that would "Kill my plants"
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