Flushing: The Myth that won't Die

[trailanimal]

good discussion you fired up 22

 

[Kakarot]

I have argued with @sniper he still swears by flushing but the funny thing is we tried some unflushed and I was like what did you think about it was it good? and he was like yeah it smells like grapes when you bust a nug open and burns white.. I was like guess what I really did not flush her I ran the water through but then chopped 3 hours later... Then we got into a big ass debate lmao....

 

[trailanimal]

Of all the garden myths that exist, I hate this one the most! I'll do my best to drive nails in its coffin, once and for all!

So first, I'm going to give you a little information, then, DO your homework! This can't be answered in a paragraph, you need to get some in depth information.

I'm providing a link to a piece Read Spear posted on his website: Sativa Magazine. I This page includes links for reposting so this material is shareable. also emailed him today about posting excerpts from his book: Marijuana Cultivation Reconsidered. This page includes links for reposting

Science is Truth!

Roots and Fluids: A Primer
Read Spear | October 29, 2014 | Growing, Growing Tips, Technical | No Comments

Roots do not work like sponges. They are picky about what they bring into the plant. Here is Chapter 8: “Roots and Plant Hydraulics” from my new book, Marijuana Cultivation Reconsidered.

Why You Need to Know: All manner of foolishness flourishes when growers fail to understand how roots take up water and nutrients, or how water and nutrients move throughout the plant. Don’t be one of the fools.

It is worthwhile to know a few things about ground tissues. Understanding how they work will save you money when you shop for products that claim to sweeten your buds or when you sort through the advice offered indiscriminately on the Internet.

The root is comprised of four nested layers of tissue: the outermost layer is the epidermis; just inside that layer is the cortex; this is followed by the endodermis; and finally, at the core, is the stele. There are also root hairs, which are extensions of the epidermis which serve to greatly increase the root’s surface area. And, finally, at the growing tip of the root (the meristematic region) are specialized cells known as the root cap. Some truly amazing things go on in the root cap. None other than Charles Darwin understood the root cap of the plant to function “like the brain of one of the lower animals.”32 33 34 The root cap can detect:

water
gravity
toxic chemicals
nutrient
light
pressure
bacteria
fungus
rock/inanimate objects
other plants
other members of its own species
its own roots
In short, this is an amazing part of the plant.



Roots bring water and nutrients into the plant using osmosis to absorb water, and active transport to absorb nutrients. (Note the use of the word “absorb”–with a B–which connotes transport across a barrier and into another space. When we consider soil properties in a later section of this book, we will discuss adsorption–with a D–which means to stick onto, rather than transport into.) This fact is worth emphasizing: Roots use osmosis to absorb water, and active transport to absorb nutrients.

Counterintuitively, water and nutrients do not enter together with the ions that are dissolved in water. That’s an important point to remember. They enter separately. The second point to remember is that plants do not use nutrients in their organic form. They cannot use nutrients until they have been broken down into their inorganic form. We will get into that later in the book, just note it for now.

An additional mechanism is used within the plant to move water and other solutions around. That mechanism is called convection. So, that’s three ways of moving water into and through the plant: osmosis, active transport and convection (where the first two bring water into the plant and the third moves it around). Let’s have a look at each.

Understanding osmosis is critical to your understanding of roots. Please take the time to comprehend osmosis because doing so will serve you in many ways as a gardener. To begin, it will help to become familiar with a few terms:

Solute: This is the stuff that gets dissolved. Here, we mean mineral solids (nutrients)

Solvent: This is the stuff that dissolves the solute. In this case, we mean water

Solution: A combination of solute and solvent

Dilute: Lacking in, or having a low level of, solute

Concentrate: High in solute

Osmosis is the transportation of solvent through a semi-permeable membrane and into a concentration of higher solute in whichever direction will enable it to equalize concentration on either side of the membrane.

We always want osmosis to create pressure (which results in turgor, or the stiffening of pressurized tissue) in the plant cell. This causes the plant to stand upright.

Osmosis becomes a factor when the dissolved chemicals on one side of a semi-permeable membrane cannot pass through the membrane in order to equalize concentrations. Instead, water moves through to achieve the same result. Hence:

If the plant cell has a high concentration of solute (think dissolved nutrient) and the water outside the cell has a low concentration of solvent (think pure water), we describe that cell as being in a hypotonic solution and the plant cell will absorb water, resulting in turgid plant tissue.

If, on the other hand, the plant cell has a high level of solvent and the material surrounding the cell has a high concentration of solute, we describe that cell as being in a hypertonic solution and the plant cell will lose water, resulting in flaccid plant tissue.

When a plant cell is in a solution equal in concentration to the fluid surrounding it, it is said to be in an isotonic solution. This does not mean that no transport is occurring; it means that “water in” is in balance with “water out.”



Active transport costs the plant energy; that’s why it’s called “active.” Active transport is the use of chemical energy (ATP in this case) in order to move solution against the concentration gradient. That means moving mineral nutrient ions from an area of low concentration into an area of high concentration, or, in other words, not equalizing the concentration but instead creating a greater concentration disparity–just in the opposite direction of osmosis.

Plants need to engage in active transport after they have exhausted their ability to absorb nutrient through diffusion. (In contradistinction to osmosis, diffusion is simply the tendency of molecules to evenly distribute themselves; for example, in the way an odor can become detectable at a distance from where it originated.) Since the plant’s need for ionic nutrient is greater than the supply available outside the plant in the soil, the plant must have a way to move that nutrient beyond equilibrium and against a concentration gradient.



Plants are able to do this by using ATP to change the shape of proteins in the cell membranes. When the proteins change shape they are able to bind to ionic (charged) nutrients and deposit them on the opposite side of the membrane, which, in turn, causes another change in protein shape and results in another transport of ions, this time in the other direction. Simply put, there’s a trade. After the trade has occurred, an additional ATP molecule is needed to repeat the process.



Plants use H⁺ (hydrogen) and OH⁻ (hydroxyl) ions, which are products of plant metabolism, to trade for mineral nutrient ions that adhere to soil particles, such as NO3⁻ (nitrate) or K⁺ (potassium). This mechanism is so effective that plants are able to move some nutrients against a gradient with a difference in concentration of 10,000 times!35 Plants do not secrete H⁺ (hydrogen) and OH⁻ (hydroxyl) ions in equal measure; instead they tend to favor H⁺, which means that the plant is actively acidifying its soil (this occurs in addition to decomposition and consequent carbonic acid accumulation.) We will get into this a little more later on because it has implications when you mix or buy potting soil.

Convection is the loss of water through the leaves of the plant. This loss creates a lower pressure gradient at the top of the plant which the water moves toward in order to fill. This phenomenon of the plant pulling water upward is called the Cohesion-Tension (or C-T) mechanism and it is the primary mechanism for moving water through a plant.

Water sticks to itself because of its hydrogen bonds (cohesion). In the small tubes of the xylem, these bonds provide enough tension to enable the low pressure at the top of the plant to literally pull water great distances upward without ever breaking this tension.



In Summary: Roots are amazing, almost “smart” things. Osmosis, active transport and convection carry water and nutrients into and throughout the plant. Plants do not absorb nutrient broth the way a sponge soaks up water from a countertop; mineral nutrient ions and water enter separately. Excessive concentrations of nutrient solution in the soil can reverse the direction of osmosis, killing your plant. Understanding how uptake and transport mechanisms work also resolves the question of whether or not you need to “flush” at the end of each growing cycle. Flushes are pure nonsense, as you now know. Only someone without an understanding of these transport mechanisms would claim differently.

32. Darwin, C., & Darwin, F. (1897). The power of movement in plants. Appleton.
33. Barlow, P. W. (2006). Charles Darwin and the plant root apex: closing a gap in living systems theory as applied to plants. In Communication in Plants (pp. 37-51). Springer
34. Baluska, F., Mancuso, S., Volkmann, D., & Barlow, P. W. (2009). The ‘root-brain’ hypothesis of Charles and Francis Darwin: Revival after more than 125 years. Plant Signal Behav, 4(12), 1121-1127.
35. Taiz, L., & Zeiger, E. (2010). Plant Physiology, Fifth Edition (Fifth ed.). Sinauer Associates, Inc.

thanks for the primer! An understanding of nutrient absorption by a plant will help to grow a healthy plant, just as understanding the processes of nutrient absorption within a human digestive system will help grow a healthy body.

 

[Corgy]

You keep busting them pop22!
I only flush when i have been to the bathroom!

...........

............

 

[Eyes on Fire]

I love that since I have had the same idea gthat its purely just a waste of water. its funny cuz when I grew chems I naturally either knew this or just felt and tasted the no difference deal so I never flushed. always did the cleanse or rinsing of a soil as I call it. LOL! gotta love it ! ill get on that book thing right now..bbiab

 

[Bailey]

Of all the garden myths that exist, I hate this one the most! I'll do my best to drive nails in its coffin, once and for all!

So first, I'm going to give you a little information, then, DO your homework! This can't be answered in a paragraph, you need to get some in depth information.

I'm providing a link to a piece Read Spear posted on his website: Sativa Magazine. I This page includes links for reposting so this material is shareable. also emailed him today about posting excerpts from his book: Marijuana Cultivation Reconsidered. This page includes links for reposting

Science is Truth!

Roots and Fluids: A Primer
Read Spear | October 29, 2014 | Growing, Growing Tips, Technical | No Comments

Roots do not work like sponges. They are picky about what they bring into the plant. Here is Chapter 8: “Roots and Plant Hydraulics” from my new book, Marijuana Cultivation Reconsidered.

Why You Need to Know: All manner of foolishness flourishes when growers fail to understand how roots take up water and nutrients, or how water and nutrients move throughout the plant. Don’t be one of the fools.

It is worthwhile to know a few things about ground tissues. Understanding how they work will save you money when you shop for products that claim to sweeten your buds or when you sort through the advice offered indiscriminately on the Internet.

The root is comprised of four nested layers of tissue: the outermost layer is the epidermis; just inside that layer is the cortex; this is followed by the endodermis; and finally, at the core, is the stele. There are also root hairs, which are extensions of the epidermis which serve to greatly increase the root’s surface area. And, finally, at the growing tip of the root (the meristematic region) are specialized cells known as the root cap. Some truly amazing things go on in the root cap. None other than Charles Darwin understood the root cap of the plant to function “like the brain of one of the lower animals.”32 33 34 The root cap can detect:

water
gravity
toxic chemicals
nutrient
light
pressure
bacteria
fungus
rock/inanimate objects
other plants
other members of its own species
its own roots
In short, this is an amazing part of the plant.



Roots bring water and nutrients into the plant using osmosis to absorb water, and active transport to absorb nutrients. (Note the use of the word “absorb”–with a B–which connotes transport across a barrier and into another space. When we consider soil properties in a later section of this book, we will discuss adsorption–with a D–which means to stick onto, rather than transport into.) This fact is worth emphasizing: Roots use osmosis to absorb water, and active transport to absorb nutrients.

Counterintuitively, water and nutrients do not enter together with the ions that are dissolved in water. That’s an important point to remember. They enter separately. The second point to remember is that plants do not use nutrients in their organic form. They cannot use nutrients until they have been broken down into their inorganic form. We will get into that later in the book, just note it for now.

An additional mechanism is used within the plant to move water and other solutions around. That mechanism is called convection. So, that’s three ways of moving water into and through the plant: osmosis, active transport and convection (where the first two bring water into the plant and the third moves it around). Let’s have a look at each.

Understanding osmosis is critical to your understanding of roots. Please take the time to comprehend osmosis because doing so will serve you in many ways as a gardener. To begin, it will help to become familiar with a few terms:

Solute: This is the stuff that gets dissolved. Here, we mean mineral solids (nutrients)

Solvent: This is the stuff that dissolves the solute. In this case, we mean water

Solution: A combination of solute and solvent

Dilute: Lacking in, or having a low level of, solute

Concentrate: High in solute

Osmosis is the transportation of solvent through a semi-permeable membrane and into a concentration of higher solute in whichever direction will enable it to equalize concentration on either side of the membrane.

We always want osmosis to create pressure (which results in turgor, or the stiffening of pressurized tissue) in the plant cell. This causes the plant to stand upright.

Osmosis becomes a factor when the dissolved chemicals on one side of a semi-permeable membrane cannot pass through the membrane in order to equalize concentrations. Instead, water moves through to achieve the same result. Hence:

If the plant cell has a high concentration of solute (think dissolved nutrient) and the water outside the cell has a low concentration of solvent (think pure water), we describe that cell as being in a hypotonic solution and the plant cell will absorb water, resulting in turgid plant tissue.

If, on the other hand, the plant cell has a high level of solvent and the material surrounding the cell has a high concentration of solute, we describe that cell as being in a hypertonic solution and the plant cell will lose water, resulting in flaccid plant tissue.

When a plant cell is in a solution equal in concentration to the fluid surrounding it, it is said to be in an isotonic solution. This does not mean that no transport is occurring; it means that “water in” is in balance with “water out.”



Active transport costs the plant energy; that’s why it’s called “active.” Active transport is the use of chemical energy (ATP in this case) in order to move solution against the concentration gradient. That means moving mineral nutrient ions from an area of low concentration into an area of high concentration, or, in other words, not equalizing the concentration but instead creating a greater concentration disparity–just in the opposite direction of osmosis.

Plants need to engage in active transport after they have exhausted their ability to absorb nutrient through diffusion. (In contradistinction to osmosis, diffusion is simply the tendency of molecules to evenly distribute themselves; for example, in the way an odor can become detectable at a distance from where it originated.) Since the plant’s need for ionic nutrient is greater than the supply available outside the plant in the soil, the plant must have a way to move that nutrient beyond equilibrium and against a concentration gradient.



Plants are able to do this by using ATP to change the shape of proteins in the cell membranes. When the proteins change shape they are able to bind to ionic (charged) nutrients and deposit them on the opposite side of the membrane, which, in turn, causes another change in protein shape and results in another transport of ions, this time in the other direction. Simply put, there’s a trade. After the trade has occurred, an additional ATP molecule is needed to repeat the process.



Plants use H⁺ (hydrogen) and OH⁻ (hydroxyl) ions, which are products of plant metabolism, to trade for mineral nutrient ions that adhere to soil particles, such as NO3⁻ (nitrate) or K⁺ (potassium). This mechanism is so effective that plants are able to move some nutrients against a gradient with a difference in concentration of 10,000 times!35 Plants do not secrete H⁺ (hydrogen) and OH⁻ (hydroxyl) ions in equal measure; instead they tend to favor H⁺, which means that the plant is actively acidifying its soil (this occurs in addition to decomposition and consequent carbonic acid accumulation.) We will get into this a little more later on because it has implications when you mix or buy potting soil.

Convection is the loss of water through the leaves of the plant. This loss creates a lower pressure gradient at the top of the plant which the water moves toward in order to fill. This phenomenon of the plant pulling water upward is called the Cohesion-Tension (or C-T) mechanism and it is the primary mechanism for moving water through a plant.

Water sticks to itself because of its hydrogen bonds (cohesion). In the small tubes of the xylem, these bonds provide enough tension to enable the low pressure at the top of the plant to literally pull water great distances upward without ever breaking this tension.



In Summary: Roots are amazing, almost “smart” things. Osmosis, active transport and convection carry water and nutrients into and throughout the plant. Plants do not absorb nutrient broth the way a sponge soaks up water from a countertop; mineral nutrient ions and water enter separately. Excessive concentrations of nutrient solution in the soil can reverse the direction of osmosis, killing your plant. Understanding how uptake and transport mechanisms work also resolves the question of whether or not you need to “flush” at the end of each growing cycle. Flushes are pure nonsense, as you now know. Only someone without an understanding of these transport mechanisms would claim differently.

32. Darwin, C., & Darwin, F. (1897). The power of movement in plants. Appleton.
33. Barlow, P. W. (2006). Charles Darwin and the plant root apex: closing a gap in living systems theory as applied to plants. In Communication in Plants (pp. 37-51). Springer
34. Baluska, F., Mancuso, S., Volkmann, D., & Barlow, P. W. (2009). The ‘root-brain’ hypothesis of Charles and Francis Darwin: Revival after more than 125 years. Plant Signal Behav, 4(12), 1121-1127.
35. Taiz, L., & Zeiger, E. (2010). Plant Physiology, Fifth Edition (Fifth ed.). Sinauer Associates, Inc.

absolutely amazing information bro

 

[Eyes on Fire]

@Waira here is the first part to it, im wondering if it was one of her vids..? hmm,, ill continue looking but you can also look for Elaine Ingham Ph.D. but here is the first paragraph that put me on that path to find out LOL

and this is the content pages of Marijuana Pest and Disease control from Ed Rosenthal. decent book and goves mostly all natural remedies that work. Ive used some and turned others onto others that say worked nicely for them. soooo better than pouring bleach on em eh?!LMFAO!! ok not really bleach but might as well be LOL

 

[Waira]

:smoking: pop', that's being a bit literalist with the terms synthetic and organic... I with you, they are all chemicals, but these terms simply distinguish their sourcing, or how they are made... Also agreed, ultimately to the plant, the nutrients end up getting absorbed in the same forms whether they came from organic or synthetic sources,... synthetic to me means man-made, manufactured,...organic generally means coming from actual organic/biologically derived sources... for those components that even truly qualify as being distinguishable as "organic"- -- a term badly abused out there!
Well, for my part, I'm not talking about total depletion, I'm referring to potentially excess amounts of accumulated nute elements,... I agree, the plant at the end of life is gathering up and using everything it can to maximize it's chances of reproducing successfully, hence the tapping out of the fan leaves, even though that process itself is energetically costly... I don't know what you mean by buds living on after the plant dies,.. (might be we see "live" and 'die" under different definitions- ).. you talking about post harvest "death throes" breakdown, etc.? Or do you mean that even if, say, the roots are wiped out, the buds can carry on for a while by using other internal resources? That's true enough, but I disagree with the "long time" part of it,.. such an event is of course a death sentence, but the effect isn't instantaneous (technically- LOL!)...
Flushing doesn't always FUBAR the pH, and when folks come to the Infirmary with roasted, badly overfert'ed, off pH plants, the only way to fix it fast enough to save them is to flush and purge the excesses... it has saved many plants brudda, honest! It's the lesser of evils often,... Usually I tell them to pH the water if needed, depending on the issue and their water source/chemistry, and sometimes to put a weak dose of nutes in the final pour to avoid triggering deficiencies,...
... Interesting deal with chelation,... I don't know either if the whole matrix surrounding the ionic element is taken in, or if it's disassembled at the point of contact,... again it goes to the "lock and key" specific mechanism by which select ions are recognized, bound and taken in,... for sure, the chelators are keeping the charge state of that ion the same, since they don't form actual chemical bonds with it,... some of those ions, especially the metals like Fe and Zn are rather reactive and could easily get tangled up in another formed compound before they get inside the cells,...
Mg sparks from smoking?? Oh, that's comedy there! ..like there's ground elemental Mg in there, and a bloody heat source hot enough to ignite it!

>> Kakarot- I can just picture that debate! Sniper is wiser than he looks.... never argue with your mentor! Cheers bro'...

>>

 

[F.N.]

You

Aye, and funnily enough I was just laughing with the guys at the grow shop about the all the nutes and stuff some folk buy. They don't stock AN 'cos of the amount of shelf space it needs and have never tried to sell me supplements. Once they refused to sell me pH up when I though I needed it for a soil grow and also told me not to starve plants at the end.

All I bought was IONIC hydro bloom and a new 600W HPS kit for £65 so I can add another light to try out aeroponics under:smoking:

Might be a little OT for this thread but how would I go about finding out how much one notch above not enough is in an active reservoir? The nute company says run at 2.0 on the EC but I suspect that's just how much they want me to use so I use more of their product.

You have a top knotch growshop pop2w my guys are similar i have been dealing with the same dudes since 1995 I go no where else

 

[nicecoolbud]

I have been thinking about trying to grow some chilies like the Ghost Pepper or the Bhut Joklia ? how ever you spell the shit.. That would be pretty cool

I don't really know much about ghost chilies nor the newer fire breathing monsters but I've got some heirloom scotch bonnet seeds that I've been hording that produce a sweet chili that'll make dried paint weep. And that's plenty hot enough for me.