Is Pre-harvest Flushing A Myth?

[macdiesel]

Flushing in dirt isn't flushing. It's simply watering too much

 

[Maniac]

I'm very new to growing with only a handful of harvests under my belt. I try to stay open minded with advice but I hear entirely too much pseudo-science especially with flushing and ash testing. Even worse with misinformation about co2, lights, media, etc. Just had to thank you legit farmers in here who have the experience and science behind your advice, saved my ass multiple times.

 

[Kot]

I think the industry have pushed high phosphorus bloom formulas and boosters so the plants are overfed with phosphorus. If such a plant is not starved of nutrients in the end it is harsh to smoke. Or at least I think so.

The CEO of a large ferts company have confessed that cannabis doesn't need that much P but they still must put it in exess into their products because the cannabis community believes in the large quantities of P during bloom...

I'm sure if a plant is not overfed during the bloom phase it does not need starving in the end.

The nutrients are moved through the stems to the leaves and not stored in the pastils or calyxes of the flowers or buds. The chlorophyll is also in the leaves and not in the pastils or calyxes of the buds. So trim and manicure your buds for no chemical and harsh taste.

 

[RalloD.Eno]

the chlorophyll is also in the calyxes. if it's green there's chlorophyll.

 

[Douglas.C]

No matter what stage of flower, when you chop dry and smoke the flowers, they should have a clean off-white ash and be fluffy. Anything less and your mix is wrong or your nute strength is too high. There should not be sparkling from too much magnesium or be dark and heavy with excess nutrients.

Cannabis is NOT a vegetable. I am unable to stress this enough. Talking about flushing vegetables in comparison to cannabis is like comparing tune-up specs between a piston engine and a jet engine. The subjects are completely different, in most respects.

Cannabis does NOT selectively grab "just what it needs," and organic or refined mineral nutrition does not matter. Anyone who thinks differently is obviously overlooking the majority of "Organic' grows online showing massively overfed plants. I have yet to come across a strain of cannabis that was producing quality cannabis flowers while dark green.

Cannabis absorbs a whole lot more than just elements it requires for growth. These excess elements, along with any elements available in greater quantities than the plant needs, are permanently locked into new growth. Regardless of how you feel about flushing or fading, these elements will never flush or fade out.

So, if your nutrient mix is off, the excess element exceeding reserve capacities for the plant will get stored in new growth without being used. Sucking up excess elements not needed for growth? They're going to be in the end flowers as a contaminant. Flushing will not 'fix' any of this.

I run DWC. The last 5 days of flower I swap out the nutrient solution for plain r/o. The nutrient strength is usually about 100ppm or so, from the dregs I don't bother pumping out. Within 5 days, osmotic pressure evens out the solution strength between the sap in the plants and the solution in the res. It usually ends up around 400ppm, which is actually quite a bit of nutrient.

The majority of those nutrients are from the sap of the plants, emptying the reserve storage for each element. I would imagine *some* of it comes from *mobile* elements, not many though.

When grown cleanly throughout flower and then a short flush to draw out excess, the results burn so clean it has almost zero 'burnt plant' taste when smoked. The last hit in the bowl is just as tasty and flavorful as the first hit. Definitely a delicious treat. :)

Douglas

 

[Douglas.C]

Again, I have personally found that moisture is the largest factor in white ash. Also, if there is a lot of resin, the ash tends to stay black (prevents plant matter from fully combusting?), IME.

Moisture as in how?

You can clip wet bud, at any time during my flower runs, and simply roast it to a fluffy, off-white ash. The only time I get a dark ash is when I mess up the flowering run in some way with the nutes.

High Resin Content? I have that...
My methods produce cannabis so resinous it drips from the end of the joint with most strains. I have exactly zero issues with complete combustion and the ash is light and fluffy, drops out with a puff of air or gentle tap.

Douglas

 

[Savage Henry]

No matter what stage of flower, when you chop dry and smoke the flowers, they should have a clean off-white ash and be fluffy. Anything less and your mix is wrong or your nute strength is too high. There should not be sparkling from too much magnesium or be dark and heavy with excess nutrients.

Cannabis is NOT a vegetable. I am unable to stress this enough. Talking about flushing vegetables in comparison to cannabis is like comparing tune-up specs between a piston engine and a jet engine. The subjects are completely different, in most respects.

Cannabis does NOT selectively grab "just what it needs," and organic or refined mineral nutrition does not matter. Anyone who thinks differently is obviously overlooking the majority of "Organic' grows online showing massively overfed plants. I have yet to come across a strain of cannabis that was producing quality cannabis flowers while dark green.

Cannabis absorbs a whole lot more than just elements it requires for growth. These excess elements, along with any elements available in greater quantities than the plant needs, are permanently locked into new growth. Regardless of how you feel about flushing or fading, these elements will never flush or fade out.

So, if your nutrient mix is off, the excess element exceeding reserve capacities for the plant will get stored in new growth without being used. Sucking up excess elements not needed for growth? They're going to be in the end flowers as a contaminant. Flushing will not 'fix' any of this.

I run DWC. The last 5 days of flower I swap out the nutrient solution for plain r/o. The nutrient strength is usually about 100ppm or so, from the dregs I don't bother pumping out. Within 5 days, osmotic pressure evens out the solution strength between the sap in the plants and the solution in the res. It usually ends up around 400ppm, which is actually quite a bit of nutrient.

The majority of those nutrients are from the sap of the plants, emptying the reserve storage for each element. I would imagine *some* of it comes from *mobile* elements, not many though.

When grown cleanly throughout flower and then a short flush to draw out excess, the results burn so clean it has almost zero 'burnt plant' taste when smoked. The last hit in the bowl is just as tasty and flavorful as the first hit. Definitely a delicious treat. :)

Douglas

Fuckin' a, man. From what I understand cannabis is a dynamic accumulator, and this can be used for phytoremediation ()

 

[Douglas.C]

Fuckin' a, man. From what I understand cannabis is a dynamic accumulator, and this can be used for phytoremediation (http://rydberg.biology.colostate.edu/phytoremediation/2012/Phytoremediation with hemp by Laura Cascardi.pdf)

Exactly.

Cucumbers from heavily amended organic soil are delicious!
Cannabis from heavily amended organic soil is dark, low yielding and lacking in significant terpene and cannabinoid production. Exactly the same as you get from excess nutrient hydro grows.

The longer one believes a lie, the stronger their emotional reaction is to the truth. Humans are wired that way.

Douglas

 

[MidwestToker]

So how many of you have found certain strains that no matter what you do they never burn with a white ash?
I have.

 

[Paul Simon]

I asked about pre harvest flushing and black ashes a very well respected 40+ year grower gave me this answer:

Chlorophyll b is the 'type' found in plants as we're defining it. Other structures are found in algae, cyanobacteria, et al.



Here is the molecular formula - C55H70O6N4Mg so we're looking at 55 Carbon ions, 70 Hydrogen ions, 6 Oxygen ions, 4 Nitrogen ions and 1 Magnesium ion. All 6 forms of chlorophyll have one consistent dynamic, i.e. a single Magnesium ion. Not two, not three - one. So much for the mythology about magnesium-hungry plants or worse in the wacky weed world where specific 'strains' can be magnesium-hungry. Looking at just chlorophyll b a better myth would be carbon-hungry or hydrogen-hungry and maybe even oxygen-hungry and nothing to do with magnesium.

My understanding of this worst example of stoner science is that by dumping copious amounts of water somehow water with it's simple H2O formula is able to reach up from the root zone then into a plant's vascular system and deconstruct a fairly complex molecule - that must be some really unique water indeed!

In a dynamic called translocation plants can and do move materials from leaves to other tissues - that is established botany. Plants produce carbohydrates (sugars) in the leaves by photosynthesis but non-photysynthetic parts of the plant also require carbohydrates and other organic and nonorganic materials. It's for this reason that nutrients are translocated from sources (regions of excess carbohydrates, primarily matures leaves) to what are called sinks.

Some important sinks are roots, flowers, fruits, stems and developing leaves. Leaves are particularly interesting in the translocation process because they are sinks when they are young and become sources later when they are about half-grown.

Carbohydrates are simply Carbon, Hydrogen and Oxygen molecules, i.e. simple sugars.

So let's say for sake of silliness that flushing can trigger translocation which must be a real threat for rice plants, where are the chlorophyll molecules going? They can't be destroyed because they're elements which cannot be destroyed or changed unless of course we're talking about cannabis which has special properties that negate almost every law of botany, biology, chemistry, physics imaginable.

My simple question is this: once this special water deconstructs the chlorophyll compound where do the ions go? Into thin air? That would be difficult since Magnesium is a metallic element but again we have to suspend even common sense to shore-up the flushing argument so who knows? Perhaps a special air canopy is created from flushing which can move magnesium around at will.

Even if water could deconstruct and force translocation of elements doesn't that defeat the purpose in the first place which is claimed that flushing will remove the nasties causing us to not have dank! If the mature leaves are the repository the why would you want to move these ions to the buds which you plan on consuming?

It's difficult to write this stuff without falling out of my chair with laughter. The argument fails on every level - even common sense.

Fire away! I'm wearing stainless-steel Fruit of the Loom briefs - I can take it!

This is why natural growing is the only way. You must avoid loading the plants with shit in the first place! Great thread!

 

[Douglas.C]

So how many of you have found certain strains that no matter what you do they never burn with a white ash?
I have.

No a single one.

From bagseed to elites, cannabis is the same in that respect. I would say there's something off in your mix and your plants are all stacking up excess of some element or another.

Douglas

 

[Douglas.C]

This is why natural growing is the only way. You must avoid loading the plants with shit in the first place! Great thread!

I agree completely. The easiest way I've found to do this is in hydro, with pharmaceutical grade nutrients. A full and cyclic 'Natural' pH swing and an understanding of how cannabis eats. :)

Unless I tell them different, people just assume they're smoking the cleanest and finest "All Organic" they've ever had. Love the expression on their faces when I tell them it's simply super clean hydro.

Rock On!

Douglas

 

[Paul Simon]

@Douglas.C agreed here too! Before we started going to closed loop organics, pharmaceutical grade was the only way we grew!

 

[GT21]

Theres a big difference between leaching and flushing. LEACHING is where you just water the plant for the last few weeks using up nutes. FLUSHING is where you put your plant in the bathtub and drown it trying to correct a mistake.

So how many of you have found certain strains that no matter what you do they never burn with a white ash?
I have.

I have never grown a strain that didnt burn white.

 

[Savage Henry]

I agree completely. The easiest way I've found to do this is in hydro, with pharmaceutical grade nutrients. A full and cyclic 'Natural' pH swing and an understanding of how cannabis eats. :)

Unless I tell them different, people just assume they're smoking the cleanest and finest "All Organic" they've ever had. Love the expression on their faces when I tell them it's simply super clean hydro.

Rock On!

Douglas

@Douglas.C agreed here too! Before we started going to closed loop organics, pharmaceutical grade was the only way we grew!

Where do/did you fellas source your pharma-grade fertilizer from? I looked around briefly and it appears to get quite expensive rather quickly.

 

[Douglas.C]

Where do/did you fellas source your pharma-grade fertilizer from? I looked around briefly and it appears to get quite expensive rather quickly.

General Hydroponics. Clean, Professional, Consistent for 15 years now. Love it!

 

[BudBogart]

In an outdoor environment leaching is the act of moving solubles down by percolating the soil. (Adding enough water that the soil temporarily holds extra water). Gypsum is sometimes used to facilitate the release of the solubles. In an organic grow, watering without nutes is just called "watering".
I'm not sure how people flush their potted grows, etc.

 

[Paul Simon]

Where do/did you fellas source your pharma-grade fertilizer from? I looked around briefly and it appears to get quite expensive rather quickly.

You would be surprised at what is pharma grade. House and Garden used to be, no idea if it still is. I believe Cyco is as well. AN is.

The flip side is this: elements chelated by unnatural proccess have the ability to osmotically pass through root walls, into the root system. Nutrients are alwys used in combinations by the plant and in subsequence keeping everything in balance becomes the most important aspect for feeding. Not more of any one thing, but the proper ratios of all macro and micronutrients.

 

[Quantrill]

Where do/did you fellas source your pharma-grade fertilizer from? I looked around briefly and it appears to get quite expensive rather quickly.

it is made up, fiction

 

[MidwestToker]

No a single one.

From bagseed to elites, cannabis is the same in that respect. I would say there's something off in your mix and your plants are all stacking up excess of some element or another.

Douglas

Then I would question you're true knowledge on marijuana strains and the associated Turpienes and Flavonoids and their boiling points.
I rarely feed over 500ppm. Most times it's in the 450ppm range at a .5 conversion scale. No heavy bloom boosters or snake oils. My total P rise is around 30ppm in flower.