Is Pre-harvest Flushing A Myth?

[Pimp T]

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!

 

[FooDoo]

Beating a dead horse. Some people flush. Others don't. Who cares. "What you eat don't make me shit"

I'm in dwc so I like to flush to get all the pretty colors into my leaves before I harvest. Nothing science or pseudo science about it. Just a personal visual appeal to me.

I don't know, but my guess would be that black or gray ash and good flavor vs chem flavor has more to do with proper drying and curing.

Just my 2 non scientific cents

 

[organix4207]

I personally grow organic and find no need to flush.........flush what ??? Lol
Do fruit and vegetable farmers flush their crops ? I don't flush my veggie garden and it tastes great! !

 

[organix4207]

In saying that , when I used to grow with traditional salt based fertilizers a flush was a must!!
I think the purpose of a flush while container gardening. Is to flush residual salt that is bonded to the soil and container.
Im no expert just my 2 cents ??

 

[Joe Fresh]

i dont flush....ive noticed better terpene profiles from healthy plants that are not super yellowed out, a little yellowing is one thing, but to starve the plants in their final weeks i dont do....i simple lower my nutes in the later stages because the plants eat less in the last 3-4 weeks of their life...depending strain....and the last feeding or 2 before harvest, i give plain water because i plan to cut the plant anyways and nutes cost money....

the fact is, in nature, plants are grown organically, organic grown foods and other plants, just like weed, are not flushed before harvest...and when we grow plants inside, or outside, we are always trying to replicate natures best day, every day...

the argument about flushing is when using chemical ferts if you dont flush the weed will taste like chemicals......FALSE..to a plant, a molecule of potassium whether chemical or organic, once its the size that the roots can take in, the plant does not know the difference, its just food that it can take in...the reason for ppl flushing their plants when using chem ferts, is because they are feeding salts to their soil, and each week or so they raise the dosage, and then come harvest time by a week or 2 befor they wanna cut, the plants soil has reached a salinity level that is hard for the plant to produce nicely, so they flush the soil/grow medium, so they can get it back to normal levels, or let the plant use up what it has in its self and soil before it gets cut...

ive never seen any large scale greenhouse or agricultural establishment flush their grow mediums, whether for peppers, tomatoes, ect....ecept when they plan to reuse the medium(coco, rockwool, ect...)..

my arguement for black ash is simple.....its the trimming, drying and curing process that will dictate your smoke quality.....not whether you flush or not...

and like i said, i have noticed a better terpene profile when i dont flush...that being said, foods like peppers and tomatoes are more nutrien dense rich foods when they are grown with the healthy correct complete fertilizer(orcanic, or a well established fertigation program)


for me, the arguement of flushing a plants medium can flush the nutes OUT of the plant, is no different that saying feeding your soil carboydrate sugars your roots will be able to take it up....

there is also the osmotic pressures to consider within the plan and its root system...when the salt levels are correct, the plants roots take in water and the plant uses potassium to help it carry out the water to the tips of the plants....when salt levels are low(not enough ferts) then the osmotic pressure within the plant is also low, so the plant will be slow in taking up water.....BUT...when the salt levels in the medium are high, or too high, the osmotic pressures within the plant force the water from within the plants back to the roots to protect them from the high salt content frying the roots....

just a thought ;)

 

[FooDoo]

.i simple lower my nutes in the later stages because the plants eat less in the last 3-4 weeks of their life

Good point. I also never drop to 0tds because thats just a huge waste of hundreds of gallons of water. I simply let the TDs slowly taper down on its own as the garden eats and the system tops off with RO. (Under current )

 

[Joe Fresh]

Good point. I also never drop to 0tds because thats just a huge waste of hundreds of gallons of water. I simply let the TDs slowly taper down on its own as the garden eats and the system tops off with RO. (Under current )

yes, because nutes are expensive, and at that point, your going to cut soon anyways, and the plants are healthy, so why not lower it, but i wouldnt lower it as much to make the plant look all unhealthy yellowish...

ime, in nature plants that turn too yellow near harvest are from the over rainy seasons, the plant let go too late, or not enough fertilizer throughout the season....color in a plant is one thing, but theres a difference between natural colors, and colors forced upon a plant from starving it.....

 

[MushinNoShin]

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!

Totally agree with you, the only reason I flush is because it seems to keep my harvest time on schedule, I.e. if I continue to feed nutes thru late-bloom it seems to prolong bloom and I have to harvest later. If I flush, it seems to trigger a ripening response in the plants.

One thing I am curious about is the Magnesium part, what your saying is logical and makes sense, but I do have a lot of cuts/strains (particularly OGs) that absolutely need Epsom Salts. They get stunted and turn yellow/golden then crunchy, slow death. Do you think it may actually be the sulphur? Would love to try and get to the bottom of this and figure-out what it is my girls actually require.

Allbeit 1 Mg ion, would there still not be a Mg requirement? I believe that Mg is required for fixation and/or synthesis (would need to brush-up on my botany/biology).

 

[MushinNoShin]

yes, because nutes are expensive, and at that point, your going to cut soon anyways, and the plants are healthy, so why not lower it, but i wouldnt lower it as much to make the plant look all unhealthy yellowish...

ime, in nature plants that turn too yellow near harvest are from the over rainy seasons, the plant let go too late, or not enough fertilizer throughout the season....color in a plant is one thing, but theres a difference between natural colors, and colors forced upon a plant from starving it.....

You may have just given me the answer to a yellowing problem I have been having; over-irrigation! Need to turn my cycle down a touch. Much thanks!

 

[rubthe nub]

@Pimp T I can virtually guarantee some strains or cuts want more Mag than others. I'm sure there are many other experienced growers that will say the same.

 

[MushinNoShin]

i dont flush....ive noticed better terpene profiles from healthy plants that are not super yellowed out, a little yellowing is one thing, but to starve the plants in their final weeks i dont do....i simple lower my nutes in the later stages because the plants eat less in the last 3-4 weeks of their life...depending strain....and the last feeding or 2 before harvest, i give plain water because i plan to cut the plant anyways and nutes cost money....

the fact is, in nature, plants are grown organically, organic grown foods and other plants, just like weed, are not flushed before harvest...and when we grow plants inside, or outside, we are always trying to replicate natures best day, every day...

the argument about flushing is when using chemical ferts if you dont flush the weed will taste like chemicals......FALSE..to a plant, a molecule of potassium whether chemical or organic, once its the size that the roots can take in, the plant does not know the difference, its just food that it can take in...the reason for ppl flushing their plants when using chem ferts, is because they are feeding salts to their soil, and each week or so they raise the dosage, and then come harvest time by a week or 2 befor they wanna cut, the plants soil has reached a salinity level that is hard for the plant to produce nicely, so they flush the soil/grow medium, so they can get it back to normal levels, or let the plant use up what it has in its self and soil before it gets cut...

ive never seen any large scale greenhouse or agricultural establishment flush their grow mediums, whether for peppers, tomatoes, ect....ecept when they plan to reuse the medium(coco, rockwool, ect...)..

my arguement for black ash is simple.....its the trimming, drying and curing process that will dictate your smoke quality.....not whether you flush or not...

and like i said, i have noticed a better terpene profile when i dont flush...that being said, foods like peppers and tomatoes are more nutrien dense rich foods when they are grown with the healthy correct complete fertilizer(orcanic, or a well established fertigation program)


for me, the arguement of flushing a plants medium can flush the nutes OUT of the plant, is no different that saying feeding your soil carboydrate sugars your roots will be able to take it up....

there is also the osmotic pressures to consider within the plan and its root system...when the salt levels are correct, the plants roots take in water and the plant uses potassium to help it carry out the water to the tips of the plants....when salt levels are low(not enough ferts) then the osmotic pressure within the plant is also low, so the plant will be slow in taking up water.....BUT...when the salt levels in the medium are high, or too high, the osmotic pressures within the plant force the water from within the plants back to the roots to protect them from the high salt content frying the roots....

just a thought ;)

Couldn't have said it any better.

The root system will not uptake certain elements if it is in an organic molecule, it must be broken-down into an inorganic form for uptake and assimilation.

Remember that "organic" simply means containing Carbon and "inorganic"; w/o Carbon. I trust the purity of inorganic salts over "Organics" derived from the ocean with notoriously high heavy metal concentrations, I.e. Mercury, Cadmium, etc. "Inorganic" is not synonymous with "toxic", I think a lot of people are confused by this.

These heavy metals make their way up the food chain and onto land (think bat guano and blood meal) and in higher concentrations. Yea, I'll stick to my "chemicals". Pure H2O can technically be called a chemical, everything can.

Imvh personal opinion, it is the most ingenious marketing scam of our generation; "Organic Food", lmao! As opposed to what?

The color of your ash has more to do with moisture (dry/cure) than anything else.

 

[Joe Fresh]

Imvh personal opinion, it is the most ingenious marketing scam of our generation; "Organic Food", lmao! As opposed to what?

The color of your ash has more to do with moisture (dry/cure) than anything else.

well i must actually point out, that a well established organic garden(for fruits and veggies) that has optimum soil with a huge variety of amendments, will produce more nutrient dense foods....this means vs a normal veggie grown in soil with added complete chem ferts, the organic veggie will contain a higher number of vitamins for you when you eat it...brix is another thing too...

nay if there is 6 different sources of nitrogen that get broken down in different ways at different times, then the plant will be able to absorb N much easier...with organics its not about one thing, but a combination of things and microbes...

cant say much about weed in this situation, but i would assume its similar

 

[MushinNoShin]

well i must actually point out, that a well established organic garden(for fruits and veggies) that has optimum soil with a huge variety of amendments, will produce more nutrient dense foods....this means vs a normal veggie grown in soil with added complete chem ferts, the organic veggie will contain a higher number of vitamins for you when you eat it...brix is another thing too...

nay if there is 6 different sources of nitrogen that get broken down in different ways at different times, then the plant will be able to absorb N much easier...with organics its not about one thing, but a combination of things and microbes...

cant say much about weed in this situation, but i would assume its similar

Makes sense. I still use organics, don't get me wrong, gives conplex flavors and terpene profiles.

 

[MushinNoShin]

Definitely curious about the Mg thing, @Pimp T has a very valid point that I never realized before.

 

[Pimp T]

I think you may need calcium sulfate for a fix for that og problem @MushinNoShin

 

[FooDoo]

Just a little update. I'm not a stubborn idiotic mule like most growers on this site so I wanted to test this theory out. I'm growing a triangle kush x bubba kush from csi Humboldt and am 2 days away from ending week 8. Most "hurry up" growers would have been flushing by now and looking to harvest in 2 days. I'm in dwc with a blue lab so I can monitor how much the girls are eating.

My stew was getting old at 650 tds and didn't want to add back ontop of that so yesterday before lights on I dumped most of the under current system and rediluted with RO with an ending tds of 200. I then added a weak solution of fresh nutes that got me around 420 tds. In dwc, if ph rises on a fresh batch over night it means the girls are hungry, if it stays the same it means perfect tds and if it drops drastically over night it means the fresh batch was too hot. This morning the tds is 350 and ph climbed from 5.5 to 5.7. This tells me my indicas in week 8 are still eating like crazy.

By what the numbers are showing me, I'm starting to think that all those years I've been doing two week flushes has really not been beneficial to my girls.

 

[Joe Fresh]

yep, flushing is wrong, the key is to not over feed them, and usually late in flower they slow down on their eating, so you would normally drop the food as well so it wont accumulate(in a medium, not dwc, lol)..this is to keep the plant healthy and this way you know your not over feeding by lowering the nutes, and your not starving the plant by flushing.....lowering nutes is the right way...your dwc should show you when that strain likes to stop eating, or slow down

 

[FooDoo]

I'm thankful for all the curious minds on this site that like to question common practices and back it up with evidence and science. Those are far and few between.

Because of them, I'm growing like ive never grown before by using higher humidity and monitoring vpd, using less co2, and now from this thread, creating better meds by not flushing so early and starving my plants in a time where they are clearly still eating like crazy .

I've also come across a thread recently, with a science study attached, saying mh for vegging is also a myth. We ate under the impression that mh creates shorter bushier veg plants where science says its simply not true. I've always vegged under mh but plan to veg under hps after this harvest. That would save a couple hundred dollars easily with not having to buy two sets of bulbs.

 

[Joe Fresh]

I'm thankful for all the curious minds on this site that like to question common practices and back it up with evidence and science. Those are far and few between.

Because of them, I'm growing like ive never grown before by using higher humidity and monitoring vpd, using less co2, and now from this thread, creating better meds by not flushing so early and starving my plants in a time where they are clearly still eating like crazy .

I've also come across a thread recently, with a science study attached, saying mh for vegging is also a myth. We ate under the impression that mh creates shorter bushier veg plants where science says its simply not true. I've always vegged under mh but plan to veg under hps after this harvest. That would save a couple hundred dollars easily with not having to buy two sets of bulbs.

its funny, the guy i learned form, is a proffessional commercial cropper that has had over 20 houses with 16-22 lights per house since 1987..he once gave me his recipe(close family friend) that he apparently paid 100k for back in the day...the basics of it were; feed every feeding, never flush feed until the end, and always use hps, and co2 between 900-1200 never higher...much more details, but thats the basics of what he told me..seems to still work well, ive tried other way, but to be honest that method produces the nicer healthier plants that yield more


now i realize paying 100k for someones "grow recipe" seems very nuts...but back then weed was expansive compared to now, lol...and last time i remember talking to him(been a few years) he owned his own island in the Caribbean, and had over 400k in his 3 month olds bank account for when he grows up...i guess when you got so much money you dont care to waste some

 

[organix4207]

I don't know about the scientific report. I have Veged under both personally and found that metal halide produces a much fuller canopy and basically just overall healthier plants. this was done out of necessity and lack of money for proper equipment. I'm not saying you are wrong. just wondering if the bulb in the study was some type of full spectrum HPS?