Check Out This Info I Found About Not Flushing, That's Right, Not Flushing

Just post it like this.. So we dont have to go to another site..



BELOW WAS TAKEN FROM http://cannabis.com/growing/flushing-a-critical-look-at-preharvest-flushing.html


http://marijuana-ro.com/cms/index.php?page=soil-soillessAdvanced - Flushing

A critical look at preharvest flushing

Pre harvest flushing is a controversial topic. Flushing is supposed to improve taste of the final bud by either giving only pure water, clearing solutions or extensive flushing for the last 7-14 days of flowering. While many growers claim a positive effect, others deny any positive influence or even suggest reduced yield and quality.

The theory of pre harvest flushing is to remove nutrients from the grow medium/root zone. A lack of nutrients creates a deficiency, forcing the plant to translocate and use up its internal nutrient compounds.

Nutrient fundamentals and uptake:

A good read about plant nutrition can be found here.

Until recently it was common thought that all nutrients are absorbed by plant roots as ions of mineral elements. However in newer studies more and more evidence emerged that additionally plant roots are capable of taking up complex organic molecules like amino acids directly thus bypassing the mineralization process.

The major nutrient uptake processes are:

1) Active transport mechanism into root hairs (the plant has to put energy in it, ATP driven) which is selective to some degree. This is one way the plant (being immobile) can adjust to the environment.

2) Passive transport (diffusion) through symplast to endodermis.

http://www.biol.sc.edu/courses/bio102/f99-3637.html

http://www.hort.wisc.edu/cran/Publications/2001 Proceedings/min_nutr.pdf

The claim only ‘chemical’ ferted plants need to be flushed should be taken with a grain of salt. Organic and synthetic ferted plants take up mineral ions alike, probably to a different degree though. Many influences play key roles in the taste and flavor of the final bud, like the nutrition balance and strength throughout the entire life cycle of the plant, the drying and curing process and other environmental conditions.

3) Active transport mechanism of organic molecules into root hairs via endocytosis.

http://acd.ucar.edu/~eholland/encyc6.html

Here is a simplified overview of nutrient functions:

Nitrogen is needed to build chlorophyll, amino acids, and proteins. Phosphorus is necessary for photosynthesis and other growth processes. Potassium is utilized to form sugar and starch and to activate enzymes. Magnesium also plays a role in activating enzymes and is part of chlorophyll. Calcium is used during cell growth and division and is part of the cell wall. Sulfur is part of amino acids and proteins.

Plants also require trace elements, which include boron, chlorine, copper, iron, manganese, sodium, zinc, molybdenum, nickel, cobalt, and silicon.

Copper, iron, and manganese are used in photosynthesis. Molybdenum, nickel, and cobalt are necessary for the movement of nitrogen in the plant. Boron is important for reproduction, while chlorine stimulates root growth and development. Sodium benefits the movement of water within the plant and zinc is neeeded for enzymes and used in auxins (organic plant hormones). Finally, silicon helps to build tough cell walls for better heat and drought tolerance.

http://www.sidwell.edu

You can get an idea from this how closely all the essential elements are involved in the many metabolic processes within the plant, often relying on each other.

Nutrient movement and mobility inside the plant:

Besides endocytosis, there are two major pathways inside the plant, the xylem and the phloem. When water and minerals are absorbed by plant roots, these substances must be transported up to the plant's stems and leaves for photosynthesis and further metabolic processes. This upward transport happens in the xylem. While the xylem is able to transport organic compounds, the phloem is much more adapted to do so.

The organic compounds thus originating in the leaves have to be moved throughout the plant, upwards and downwards, to where they are needed. This transport happens in the phloem. Compounds that are moving through the phloem are mostly:
Sugars as sugary saps, organic nitrogen compounds (amino acids and amides, ureides and legumes), hormones and proteins.

http://www.sirinet.net

Not all nutrient compounds are moveable within the plant.

1) N, P, K, Mg and S are considered mobile: they can move up and down the plant in both xylem and phloem.
Deficiency appears on old leaves first.

2) Ca, Fe, Zn, Mo, B, Cu, Mn are considered immobile: they only move up the plant in the xylem.
Deficiency appears on new leaves first.

http://generalhorticulture.tamu.edu

Storage organelles:

Salts and organic metabolites can be stored in storage organelles. The most important storage organelle is the vacuole, which can contribute up to 90% of the cell volume. The majority of compounds found in the vacuole are sugars, polysaccharides, organic acids and proteins though.

http://jeb.biologists.org.pdf

Translocation:

Now that the basics are explained, we can take a look at the translocation process. It should be already clear that only mobile elements can be translocated through the phloem. Immobile elements cant be translocated and are not more available to the plant for further metabolic processes and new plant growth.

Since flushing (in theory) induces a nutrient deficiency in the rootzone, the translocation process aids in the plants survival. Translocation is transportation of assimilates through the phloem from source (a net exporter of assimilate) to sink (a net importer of assimilate). Sources are mostly mature fan leaves and sinks are mostly apical meristems, lateral meristem, fruit, seed and developing leaves etc.

You can see this by the yellowing and later dying of the mature fan leaves from the second day on after flushing started. Developing leaves, bud leaves and calyxes don’t serve as sources, they are sinks. Changes in those plant parts are due to the deficient immobile elements which start to indicate on new growth first.

Unfortunately, several metabolic processes are unable to take place anymore since other elements needed are no longer available (the immobile ones). This includes processes where nitrogen and phosphorus, which have likely the most impact on taste, are involved.

For example nitrogen: usually plants use nitrogen to form plant proteins. Enzyme systems rapidly reduce nitrate-N (NO3-) to compounds that are used to build amino-nitrogen which is the basis for amino acids. Amino acids are building blocks for proteins, most of them are plant enzymes responsible for all the chemical changes important for plant growth.

Sulfur and calcium among others have major roles in production and activating of proteins, thereby decreasing nitrate within the plant. Excess nitrate within the plant may result from unbalanced nutrition rather than an excess of nitrogen.


Summary:

Preharvest flushing puts the plant(s) under serious stress. The plant has to deal with nutrient deficiencies in a very important part of its cycle. Strong changes in the amount of dissolved substances in the root-zone stress the roots, possibly to the point of direct physical damage to them. Many immobile elements are no more available for further metabolic processes. We are loosing the fan leaves and damage will show likely on new growth as well.

The grower should react in an educated way to the plant needs. Excessive, deficient or unbalanced levels should be avoided regardless the nutrient source. Nutrient levels should be gradually adjusted to the lesser needs in later flowering. Stress factors should be limited as far as possible. If that is accomplished throughout the entire life cycle, there shouldn’t be any excessive nutrient compounds in the plants tissue. It doesn’t sound likely to the author that you can correct growing errors (significant lower mobile nutrient compound levels) with preharvest flushing.

Drying and curing (when done right) on the other hand have proved (In many studies) to have a major impact on taste and flavour, by breaking down chlorophylls and converting starches into sugars. Most attributes blamed on unflushed buds may be the result of unbalanced nutrition and/or overfert and unproper drying/curing.
 

magilla gorilla

Well-Known Member
interesting read, i don't think i'll be flushing my hydro grow. i'll just ween it down to much lower ppm for last week or 2. but i was always gunna do that haha thanks for the link anyways :D
 

hymem

Well-Known Member
Yes! Its about time people start reading thinking about the subject of flushing like a science. Its funny to see the reaction on peoples faces when you tell them you dont flush. So many people swear by flushing without even attempting to study plant nutrient uptake. If anyone has a scientific take on how flushing your buds actually makes your buds "taste" better id love hear it.
 

Dirty Harry

Well-Known Member
Hmm, interesting read. I am not a botanist so I have no scientific insight to argue about that.
I am one who does flush, as that is how I learned. I feed on the high side so I flush due to that. Just like I shave my face the same way every time because that is what works for me...but I am big on the curing. In my mind, the curing makes the big difference.
If you grow hydroponic tomatoes, there is no flushing for that as it would damage the fruit.
I am open enough to give it a try on a small grow to see if there is any difference.
 

DaLeftHandMan

Active Member
interesting. im a week from harvest myself, and i just flushed because i was worried about salt buildup<-->taste issues, im a first time grower so i had no bias one way or another..one week after flushing them, ALL my buds grew a fresh new 'layer' of bud and extra-super-fuzzed up with trichs everywhere..soo...idk...im happy i did it. just sayin..^_^
 

racerboy71

bud bootlegger
great great post m8.. the only time i flush is when i drop a deuce, and think that flushing your plants does more harm then good, and its great to get a lil scientific evidence to back up my no flushing..
i never understood the reasoning behind flushing to begin with, and always thought that it was one of those wifes tales that has gotten passed down from uninformed grower to uninformed grower year after year...
 

hymem

Well-Known Member
Im with you on that one Racer. Just to get some expert insight I contacted an organic chemist that works in a lab that tests cannabis for contaminants. He said that flushing shouldnt remove anything from the buds until they've exhausted nutrients from all other sources. In other words the plant will draw nutrients (mobile nutrients) from other parts of the plant. The buds are the last place a plant will take nutrients from to save itself from starvation. You ever see a flushed plant that is all yellow except for the green buds? Its all about the cure and a balanced nutrient regiment.
 

Dirty Harry

Well-Known Member
I am starting to like this information. I have a plant in my grow with is going to be ready in two weeks while others are younger and have a long ways to go. I was going to pull it and flush hempy bucket style. I think I'll skip it for this one and see how it smokes after a few weeks cure.
 

Pureblood89

Well-Known Member
idk... i've had some unflushed buds that tasted like feces... literally. i've also eaten some recently fertilized vegetables that tasted disgusting.
 

Nunotmp

Active Member
I have yet to flush..I lower the nutes but come harvest time..plant still looks green and healthy
 

Kerovan

Well-Known Member
idk... i've had some unflushed buds that tasted like feces... literally. i've also eaten some recently fertilized vegetables that tasted disgusting.
I've had flushed buds that tasted like feces... and unflushed buds that were superb...

It's about the weed and the curing, not the flushing.
 

Ronjohn7779

Well-Known Member
Flushing has never made any sense to me. No commercial food producers flush and I've never flushed any of the veggies in my garden. Seriously, I've never tasted a difference in fruits and vegggies why would you be able to with weed.
 

The Ruiner

Well-Known Member
commercial food crop producers dont feed their crops before harvest...water yes, but the rest is handled by the plant. In soil, the plant gets to determine what it needs. The difference is the control indoor pot growers have (ie force-feeding with chelated nutes) over outdoor mega-mono-crop food producers that probably prepare the soil before planting, and not much else besides scheduled spraying.


Personally, my flush consists of RO water dosed with Cannazyme and molasses for about a week before chop. Sweet, safe, and delicious.
 

Viagro

Well-Known Member
Bud mold often results from flushing. Rather not risk it, if I can get good tasting buds without doing it. Organics for me.

This should be a sticky.

Good job.

Mandala Seeds has a good page of info on why they don't recommend flushing.
 

spandy

Well-Known Member
Non flusher here as well. Only difference I saw is I had less yeild when I flushed. They just didnt blow up that last 2 weeks like they normally did after i flushed out all the nutes. Taste and smell was the same.
 
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