Why oh Why oh Why ...

k0ijn

Scientia Cannabis
Another pre-harvest flushing thread?



Cannabis nutrient storage and transportation around the plant is very complicated. I'm not fully explaining every aspect of the processes in the following since I have already done so before (search my nick and read my previous posts on the subject);

Basically the nutrients are "stored" in the leaves and roots, fan leaves more so than sugar leaves.
Stems also contain a lot of nutrients but this is more to the fact of the xylem, phloem and other plant mechanisms being the main way of transporting water (and therefore nutrients) around.

The ratios are different depending on which nutrient we're talking about and also which supply (deficient vs critical vs abundant).
For example nitrate ions are 'stored' ~3:1 in leaves compared with the roots.
Whereas phosphate ions are 'stored' ~2:1 in roots compared with the leaves.
Suffice to say that there is a reason why fan leaves (and roots which is readily visible in hydro grows) react to overfeeding and underfeeding first and most severely.

The calyxes themselves do not contain an abundance of nutrients at any point in the growth, unless you heavily overfeed your plants. And you have to overfeed A LOT.
Most abundance nutrients by far end up in the leaves, roots and stems.
Cannabis plants are highly efficient, they use up the nutrients supplied to the calyxes very quickly, almost entirely eliminating any chances of nutrients building up in the calyxes, except for extreme cases.


Flushing is useful as an error correction method.
If you have salt buildup, nutrient solution problems or the like flushing is an easy and useful way of fixing those issues.

Pre-harvest flushing is something totally different.
The fact that some people believe that you can flush nutrients out of the calyxes (flowers) and thereby get improve taste, burn etc. of your final product is ridiculous.
It has never been scientifically proven to work. Science on nutrient storage and transportation proves it to be a false assumption and that is has NO basis in fact.
It's clear for any rational person to see that it is a myth, and it will remain so until proper scientific studies proves otherwise (which won't happen unless cannabis bio-functions and mechanism change radically for no apparent reason).



The thing that I have a problem with is close to the end of the go you do something ok. Now how long really does it take photosynthesis to process of the water/nutes to get to the buds?
Not sure if you're just having fun or being serious.
If the latter, it's ridiculous..


Im not sure if its a certain type of nute that dose it, but i can tell the difference sometimes, especially in this bit.
Certain type of nute? All nutrients are the same at molecular level, a nitrate ion is a nitrate ion.


Well if we're taking hydroponics here, then giving your plants nothing at all but straight water for the last two weeks will definitely cause your yields to suffer. On the other hand if you don't flush at all, you'll definitely be noticing it when you go to burn one. I've got my flushing process now zeroed in to five days. I'll drop straight down from 1200ppm to 400 (emptying out the rez, flushing with 10ml/gal of FloraKleen rigorously for an hour or so, then replenishing nutes) for first three days, then emptying out the reservoir again and using 5ml/gal of FloraKleen and pH'd tap water for the remainder, the ppms will have finally bottomed out somewhere around 100 right before the chop.

Causing a deficiency will affect the yield, you're quite right.
Not flushing will not negatively affect the weed 'when you burn it' in any way.
If you keep proper nutrient levels throughout the grow and you do a proper dry & cure, you will end up with premium weed. No flush can improve any taste, odour, burn etc.


from my experiences if you're not going to cure, just dry and smoke flushing or stop feeding 2 weeks prior to harvesting defenitely improves tastes.

Can you show me the scientific information backing up this theory?
As roc said, a proper dry & cure is what determines the taste and odour of your final product.


Racerboy cant be serious right??? You flush to leech the nutrients back out the plant. The pure water allows the plant to just drink and use left over food it has. Left in nutes change the tatse of the buds, slow curing, taste bad, make you couch and cause buds to spark when lit..Very basic here can see the growers and the noobs lol..No flush is like taking a fine exotic car and tossing regular octane gas in it. It ll run but not like it should.
To leech the nutrients back out of the plant?
I think you have a very erroneous view of how nutrient storage works in cannabis (and indeed in most plants).
Nutrients are not stored in the calyxes (see the first section of this post), you cannot leech nutrients 'out' of the calyxes since nutrients transported there from either the roots leaves are used up almost at the same time as delivery occurs. You will not see an abundance of nutrients in the calyxes unless you are heavily overfeeding to the point of toxicity occurring.
Which is VERY uncommon.
Most newbies might have slight deficiencies or minor abundances, most experienced growers stray as close to critical supply as they can.
In both cases none would induce abundance of nutrients in the calyxes.

The fact that you even tossed in a 'very basic here can see the growers and the noobs lol..' comment just goes to show your close mindedness and how this idea of pre-harvest flushing got stuck in your head as fact without any scientific backup of any kind (no studies, no general testing, no information).


It works great.
Can you show me the scientific information backing up this theory?
As roc said, a proper dry & cure is what determines the taste and odour of your final product.


I think flushing is a good idea.......

and

Curing slowly is a good idea..............

Flushing I think Helps in getting rid of unwanted nasty tasting chemicals etc.......

and Curing Slowly Helps the weed smell good rather that a quick cure that makes it smell like HAY!..........
Flushing is a good idea. Pre-harvest flushing (which is in no way the same as flushing in general and does not seek to perform the same goals as pre-harvest flushers claim pre-harvest flushing does) is a waste of time and the so called positive effects of doing so are unsubstantiated myths, with no basis in fact and no scientific evidence to back up the many claims.

Again, nutrients are not stored in the calyxes (flowers of the plant, what you smoke) therefore that age old argument is as invalid as it always has been.


the need to flush at the end of your flowering cycle is only needed when you grow in hydro

I grow in sunshine... use fert everytime I water @ 1/2 strength...never once flushed in flowewr in 20 yrs ...except for salt buildup in veg and I vaporize... so taste is a big concern of mine

Dont let anyone tell you that hydro grows better buds.... just heavier more condensed buds.....most of which will have a chemically taste in a vaporizer
There is no difference between soil and hydro when it comes to pre-harvest flushing.
If you grow the weed without causes deficiencies or abundance you will never need to flush anything.
No the weed will not have a chemical taste unless the strain delivers such a particular taste.
Nutrients are not stored in the calyxes.
 

MonkE

Member
k0ijn
Could you expand more on "critical state"?
I've never actually heard the term and a quick stomp through google yielded nothing but nonsense about power plants blowing up...
 

Shivaskunk

Well-Known Member
Monke,

I am pretty sure he means that a grower who knows his plants tend to give them the nutrients they need. With very little over or under fertilizing. If you understand your plants needs you will not over feed it and will never run into issues with bud quality.
 

Rumple

Well-Known Member
Ten days with pure water is all that it takes, anything less and the quality suffers. Got to be top notch.
 

cues

Well-Known Member
Another pre-harvest flushing thread?



Cannabis nutrient storage and transportation around the plant is very complicated. I'm not fully explaining every aspect of the processes in the following since I have already done so before (search my nick and read my previous posts on the subject);

Basically the nutrients are "stored" in the leaves and roots, fan leaves more so than sugar leaves.
Stems also contain a lot of nutrients but this is more to the fact of the xylem, phloem and other plant mechanisms being the main way of transporting water (and therefore nutrients) around.

The ratios are different depending on which nutrient we're talking about and also which supply (deficient vs critical vs abundant).
For example nitrate ions are 'stored' ~3:1 in leaves compared with the roots.
Whereas phosphate ions are 'stored' ~2:1 in roots compared with the leaves.
Suffice to say that there is a reason why fan leaves (and roots which is readily visible in hydro grows) react to overfeeding and underfeeding first and most severely.

The calyxes themselves do not contain an abundance of nutrients at any point in the growth, unless you heavily overfeed your plants. And you have to overfeed A LOT.
Most abundance nutrients by far end up in the leaves, roots and stems.
Cannabis plants are highly efficient, they use up the nutrients supplied to the calyxes very quickly, almost entirely eliminating any chances of nutrients building up in the calyxes, except for extreme cases.


Flushing is useful as an error correction method.
If you have salt buildup, nutrient solution problems or the like flushing is an easy and useful way of fixing those issues.

Pre-harvest flushing is something totally different.
The fact that some people believe that you can flush nutrients out of the calyxes (flowers) and thereby get improve taste, burn etc. of your final product is ridiculous.
It has never been scientifically proven to work. Science on nutrient storage and transportation proves it to be a false assumption and that is has NO basis in fact.
It's clear for any rational person to see that it is a myth, and it will remain so until proper scientific studies proves otherwise (which won't happen unless cannabis bio-functions and mechanism change radically for no apparent reason).





Not sure if you're just having fun or being serious.
If the latter, it's ridiculous..




Certain type of nute? All nutrients are the same at molecular level, a nitrate ion is a nitrate ion.





Causing a deficiency will affect the yield, you're quite right.
Not flushing will not negatively affect the weed 'when you burn it' in any way.
If you keep proper nutrient levels throughout the grow and you do a proper dry & cure, you will end up with premium weed. No flush can improve any taste, odour, burn etc.





Can you show me the scientific information backing up this theory?
As roc said, a proper dry & cure is what determines the taste and odour of your final product.




To leech the nutrients back out of the plant?
I think you have a very erroneous view of how nutrient storage works in cannabis (and indeed in most plants).
Nutrients are not stored in the calyxes (see the first section of this post), you cannot leech nutrients 'out' of the calyxes since nutrients transported there from either the roots leaves are used up almost at the same time as delivery occurs. You will not see an abundance of nutrients in the calyxes unless you are heavily overfeeding to the point of toxicity occurring.
Which is VERY uncommon.
Most newbies might have slight deficiencies or minor abundances, most experienced growers stray as close to critical supply as they can.
In both cases none would induce abundance of nutrients in the calyxes.

The fact that you even tossed in a 'very basic here can see the growers and the noobs lol..' comment just goes to show your close mindedness and how this idea of pre-harvest flushing got stuck in your head as fact without any scientific backup of any kind (no studies, no general testing, no information).




Can you show me the scientific information backing up this theory?
As roc said, a proper dry & cure is what determines the taste and odour of your final product.




Flushing is a good idea. Pre-harvest flushing (which is in no way the same as flushing in general and does not seek to perform the same goals as pre-harvest flushers claim pre-harvest flushing does) is a waste of time and the so called positive effects of doing so are unsubstantiated myths, with no basis in fact and no scientific evidence to back up the many claims.

Again, nutrients are not stored in the calyxes (flowers of the plant, what you smoke) therefore that age old argument is as invalid as it always has been.




There is no difference between soil and hydro when it comes to pre-harvest flushing.
If you grow the weed without causes deficiencies or abundance you will never need to flush anything.
No the weed will not have a chemical taste unless the strain delivers such a particular taste.
Nutrients are not stored in the calyxes.
OK, lets flip it. You show me the proof that Final flushing does not improve taste, burning etc.
 

MonkE

Member
Shiva
I assume so, which is exactly what I do. My ppm usually sits around 700-800 for the full grow. My plants get what they need and nothing more.
I'm asking him to expand on it to see if he has any more detailed information or support for the idea. It's always nice learning more technical info... Knowledge is power.
 

missnu

Well-Known Member
"Did I leave O-Hio?"...

Why would you title a post why o why o why o? Lol...I like it...
 

MonkE

Member
OK, lets flip it. You show me the proof that Final flushing does not improve taste, burning etc.
I don't doubt it would help. But it's the wrong way to do it.

You can starve and stunt your plant in order to get some improvement.

Or you can properly feed your plant and properly cure it for better yields and a better taste.

I suppose you could flush and properly cure... But it would be silly since the full potential of your weed can be found through curing already.


Would you really want to argue in support of a method that causes major deficiencies during the most explosive phase of growth? It's cool if you don't believe proper feeding without a flush is better... Just give it a try for yourself. In the end it's up to you to find your own truth. Hopefully the correct methods will stick as people begin to learn for themselves.
 

k0ijn

Scientia Cannabis
k0ijn
Could you expand more on "critical state"?
I've never actually heard the term and a quick stomp through google yielded nothing but nonsense about power plants blowing up...
Critical state is as shiva said hitting the optimum feeding solution where you are neither overfeeding nor underfeeding but reaching the optimal nutrient levels.
If you want it explained a bit further you can search my nick and check out my previous posts on nutrient storage and transportation.


OK, lets flip it. You show me the proof that Final flushing does not improve taste, burning etc.

First of all, the burden of proof lies with those claiming all the effects which there is no evidence for.
If you claim something does something you have to provide proof of it working if you want to convince people.
It's not those who say "until you show me proof of it doing what you say, I cannot believe in it" who have to proof that it doesn't do what you say it does.

That is very basically how burden of proof works. You can't just turn this burden around to please yourself or your own standpoint.
I know a lot of people do this but that doesn't make it right.

I could just as easily say to you that I believe feeding cow milk to cannabis plants during the first week of growth causes 100% increase in growth in just 1 hour.
And then, like you just did, say you should disprove that theory.
Do you get the absurdity of that standpoint? It's ridiculous really.


On the other hand, I got tired of people who kept saying stupid statements like that.
I got tired of people who don't even know how to prove their theories and therefore claim others should disprove them to prove them wrong..

Therefore I provided scientific evidence, factual evidence against pre-harvest flushing.
I did that explaining the basics of nutrient storage, how deficiencies and abundance works, how plants transport nutrients and how the basic functions of the xylem and phloem work. I used scientific studies done by educated researchers, used scientific information published in peer review journals. I did not just state my own opinion / experience on the matter.

You can find all this by doing a simple search for my nick and checking out my previous posts on the matter.

I would like to stress that I should NOT have to disprove what you guys are claiming to show it's false.
You guys should have to provide scientific evidence for what you claim, not the other way around.

But to shut you up I chose to deconstruct your entire theory on pre-harvest flushing anyway.
It was very difficult to do either.


Shiva
I assume so, which is exactly what I do. My ppm usually sits around 700-800 for the full grow. My plants get what they need and nothing more.
I'm asking him to expand on it to see if he has any more detailed information or support for the idea. It's always nice learning more technical info... Knowledge is power.
Usually you will have to raise the PPM during the grow, especially in late flowering.
Most strains will required more and more nutrients, to produce close to critical mass (100%).
It will get easier with experience to spot how the plants are doing and how many more nutrients they will be able to take.
I suggest you read what I wrote regarding pre-harvest flushing (if you want more detailed information on nutrient storage, nutrient supple/ratio (deficiency v critical v abundance)), you can find it by searching my nick on the forums, it's from quite a while back but it is there.
 

MonkE

Member
Usually you will have to raise the PPM during the grow, especially in late flowering.
Most strains will required more and more nutrients, to produce close to critical mass (100%).
It will get easier with experience to spot how the plants are doing and how many more nutrients they will be able to take.
I suggest you read what I wrote regarding pre-harvest flushing (if you want more detailed information on nutrient storage, nutrient supple/ratio (deficiency v critical v abundance)), you can find it by searching my nick on the forums, it's from quite a while back but it is there.
I don't up my ppm I just increase the frequency of feeding. I use two gallon pots so the plants are able to dry them out quicker as they reach later stages of flower, which allows me to water more. Coco is also hard to over water the further into flower the plant is.
 

cues

Well-Known Member
Well, all I know is I have tried flushing and not flushing. Not flushing did give me a bigger yield. However, I am still sat over the burn marks in the carpet from when I didn't flush and my joints did sparkler impressions. However, I am in hydro and not sure I see much point in flushing soil grows.
 

Shivaskunk

Well-Known Member
I would like some one to explain to me how flushing affects a part of the plant that never stores nutrients in the first place.
 

BigBuddahCheese

New Member
I never flush and everyone who has tasted my buds said they were the best then had, well some of them if they can stay awake! Sorry but the debate will never end, do what you want to do.

I tried both ways over the years and neither had any significant benefit. Both smoked smooth, tasted correct and burned white. I do feed my plants appropriately and not 1000+ ppms near harvest, which I truly believe is the reason someone flushed in the first place and then the mindless sheep took over and the debate began.

To further fuel your rage you even stated that some of the best weed you smoked was not flushed by the grower. BINK! The light should clicked in your empty one directional thinking head that maybe the "flush theory" is really just that a theory.
 

Rumple

Well-Known Member
I on the other hand have tried it both ways. I did not tell anyone that I did not flush the harvest. My wife noticed right away and said it tasted funny (not in a good way). I had her go back and test another jar of flushed weed and she could tell how much better it was. She could pick out the non-flushed stuff ten out of ten times. I grow the same strain from the same mom for over eight years in the same environment. My evidence and science is anecdotal at best, but it is good enough for me.

When I told Jorge Cervantes about this, he agreed that flushing improves the quality and criticized me for only flushing for ten days. Say what you want about Jorge Cervantes, but the guy grows great crops and has worked with the best growers on earth. I will take his advice over anyone in a cannabis forum.
 

Elliesdaddy

Active Member
The answers very simple, you will get a bit more yield if you do last 2 weeks still using budding nutrients instead of flushing, it's greed
 
on a side note, I did actually flush my plant yesterday. It was harvest time, so I left it in the dark for 24 hours. Flushed it with cold water, turned the a/c really far down, and left it another 24 in the dark. Chopped it earlier today. Now.... it was my first grow and it was suggested to use the cold water and dark, ( something about trich production ). And I had a slight error in judgement last week and cut most all of the fan leaves off it, In anticipation of cutting it. (which i did not ). So i added a bunch of superthrive, hoping it would give it a steroid shot, to bounce it back, so I could hold off another week. Thus, why I flushed it. < now did it take the superthrive out? Who knows. But, It was worth a shot.
 

k0ijn

Scientia Cannabis
I on the other hand have tried it both ways. I did not tell anyone that I did not flush the harvest. My wife noticed right away and said it tasted funny (not in a good way). I had her go back and test another jar of flushed weed and she could tell how much better it was. She could pick out the non-flushed stuff ten out of ten times. I grow the same strain from the same mom for over eight years in the same environment. My evidence and science is anecdotal at best, but it is good enough for me.

When I told Jorge Cervantes about this, he agreed that flushing improves the quality and criticized me for only flushing for ten days. Say what you want about Jorge Cervantes, but the guy grows great crops and has worked with the best growers on earth. I will take his advice over anyone in a cannabis forum.

If it was 10 out of 10 then surely flushing does do magic.
Personal opinion on top of personal opinion with a slight dash of useless information.


@BigBuddhaCheese
Maybe the light doesn't click on for some people?
 
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