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Flush or don’t?

CC420710

Active Member
Okay so I am a little confused on how this works. I know it’s highly debated topic but my question isn’t so much whether to but what to do if you aren’t flushing. Basically I wanna know do you keep giving nutes up to harvest if it doesn’t effect the buds? Basically If no flush when do nutes stop?
 

Remystemple

Well-Known Member
I grow in coco and didn't flush the first 2 times but did last time. I'm yet to notice a difference. I was happy to be able to feed just water for the last 4 or 5 days tho. i'm thinking there was probably a good amount of nutes in the coco when i started the flush so i'd imagine it took a couple days for them to have none left. plus they can always eat their leaves in the last day or 2.
 

Emilya

Member of the Month: Mar 2019
The problem as I see it is that we have become victims of our own popularity. Back in the day there were not many cannabis websites or books and the brave pioneers in this hobby used standard gardening techniques and old school methods. Nowadays, every dispensary has a website and grow experts abound... but are they really experts? I can name several websites and facebook pages that regularly offer horrible advice to their growers, labeling anything they can't accurately diagnose as the dreaded Tobacco Mosaic Virus, and giving bad advice about flushing.
First of all, in the last 5 years the definition of flushing has changed... a frightening percentage of new growers have no idea what it really means to flush your soil. And now, with so much confusion about flushing, many people have decided not to do it, or as was just posted, that there is no right answer to the question.
Of course there is a right answer and as the state of the art progresses, we are even wiser today than we were a decade ago about this practice, but even so, because of the proliferation of bad advice sites all over the internet, many people are still in the dark about this practice.
It used to be the quick answer on most online forums when presented with a plant problem, to flush. That has always been a problem, those with no valid advice offering this panacea to solve all problems, and oftentimes it actually worked, but as we know today it isn't always the best answer.
So first of all, what is a flush? Is it the act of giving pH adjusted water? No, that is simply watering with no nutes, it is not flushing. How about giving fluids to 20% runoff each time, cleansing the soil a little bit each time... is that flushing? Again, no... If you have a pile of salt sitting in your soil that keeps accumulating as you give more nutes, and you deplete that pile by 10% every time you water, but you in the process add back 5% with the new nutes, how much have you gained? Not much. If that pile of salt gets to the point that its starts locking out nutrients, does the incremental "flush" solve the problem? Nope.
The only true flush is to run 3x the container size in pure water through the system, dragging out the salt and debris with it. Some people even use sugar water to help dissolve the salt, so that maybe they don't have to run quite that much water through, but the goal is to clean out the soil. 10% wont do that... nor will 20%... to properly clean that medium out it takes 300%.
Do we flush our plants? No... what a silly idea this is. The notion of cleansing the plant of all nutrients before the end, giving only water for a week or (egads) two weeks, does not clean all the collected nutrients out of the plant. It does make the plant think it is dying, so it hastens the end and looks all impressive and all, but what did you sacrifice to get there? You starved the plant of nutrients, important finishing nutrients, right at the end when the plant needed that nutrition the most.
On hearing this, people defend their actions saying that their plants were just fine, great in fact, following this practice... but you can't prove something that didn't happen. These growers might be satisfied with what they ended up with, but they could have no idea to what potential that plant may have reached if it had not been starved that last 2 weeks.
Recent science has proven that water only at the end does not take the nutrients out of the plant. As stated in this thread, people who try a true 3x flush at the very end, or just water at the last week or two, can NOT taste the difference in their product. This is because we now know that neither practice affects the taste, smell, burnability or anything else about the cured product.
Old school taught us to flush at the week or 2 weeks from the end point... a true 3x flush. Why then? And then what, water only the rest of the way, or regular nutes? Here are the old school answers. I don't care what this website or that says about this; you can't always believe everything you read on the internet.
A true flush is to remove salt, debris or excess nutes from the soil... not the plant. Flushes are recommended when there is a major nute change, such as going from veg to flower, or from budset to budbuilding. Flushes are also to remove the salt that builds up in the soil as nutes break down to be used by the plants. After several weeks of heavy synthetic nutes, appreciable amounts of salt build up in the soil, so much so that it begins to restrict water uptake into the roots. Too much salt and you can actually lock out nutrients and the entire metabolism of the plant will slow down. Periodically, it is wise to clear out those salts so that your roots can work unrestricted and uptake the maximum amount of water and nutes that they are capable of.
There is no more important time to do an actual flush than that point at a week or 2 weeks before the end. The buds can swell up to twice their size and weight in that last two weeks, but in a salt restricted plant instead of rapid building of the buds at this point, a slow down in water usage and growth is seen. Doing a true flush at this point opens the floodgates, and allows the plant to draw up into the roots everything that it wants, and the difference that this final flush can make is astounding. For years and years this was common knowledge... but now people seem to have forgotten many of the old ways, and again, I blame the internet.
So after you do this final flush 2 weeks till the end, what then? You are still waiting for the final budswell to finish, the pistils to pull back and the trichomes to turn to your desired point. Water only you say? My answer is, are you daft? You give nutes to make big plants up to this point, and then you go water only at the most critical time??? Please. Use your head. This is not how to grow the best pot you can. Since we now know that the nutes do not show up in the flavor of the final product, what is stopping you from feeding the plant just as you have been doing, right up to the end? Nothing but this odd modern belief in bro science... if it comes off of youtube, it must be correct.
Sometimes, the old ways are the best ways.
Alright, I have had my say. Have a great evening everyone! :peace::love:
 

CC420710

Active Member
Okay thanks everyone I think I understand now it’s just so much contradiction out there it’s confusing. If it doesn’t affect the final results then I will be using nutes. I ended up feeding them last night and I was so glad I did. They really spruced up and starting making new growth on buds stronger smell I don’t regret the choice so far. I was just trying to figure out the truth if it affects it badly or not and so far not
 

Remystemple

Well-Known Member
Okay thanks everyone I think I understand now it’s just so much contradiction out there it’s confusing. If it doesn’t affect the final results then I will be using nutes. I ended up feeding them last night and I was so glad I did. They really spruced up and starting making new growth on buds stronger smell I don’t regret the choice so far. I was just trying to figure out the truth if it affects it badly or not and so far not
yeah i'm happy for this thread too. thanks @Emilya for the AMAZING and detailed info. it's certainly made up my mind not to bother with "flushing", but to give a nice extra sploosh once a week instead..
 

higherthehigh

Well-Known Member
I flush with a molasses mix for the last 2 weeks, let the plant finish off with what every remains are left in the plant.

I never flushed the first time properly and I played for it, tasted what I can only think would be acid, flushed ever since and got better results, but, I also tried an experiment again by not flushing one but only 1/3rd of synthetic nutrients and I could taste the same as the first time I never flushed so if always flushed for that reason.

Every mass grower in the UK that I know always flush, if they dont, there wholesalers refuse to buy it on the first taste test, the majority of mass growers also always cure for 2-4 weeks.

Try and play about with it.
 

Emilya

Member of the Month: Mar 2019
So what you are saying @higherthehigh is that for the last two weeks, every time you water you flood the soil with 3x the container size. If that is not what you are actually doing, then you are not flushing, and this is exactly the point I was making above, you are only watering with molasses. The modern usage of that word is incredibly wrong. Since you yourself could not tell the difference between a water only at the end plant and a plant given nutes right up to the end, how in the world would a wholesaler be able to tell? Yes, flush properly at the start of budswell, and then continue nutes/water/nutes/water all way to the end. Say that you flushed at the end, because you did. You will thank me if you try it... and no one will know, and they will probably think your pot is pretty darn good. People rave about my pot, and grown organically it NEVER goes without nutes. What would the wholesalers say about that, since I never have to flush?
 

higherthehigh

Well-Known Member
Sometimes I flush 3x the pot size until ppm levels end up at 80 the same as the tap, but the water coming out is scrapped instantly but I only do this in coco never did it yet in soil but I do just plain feed with water in soil with molasses.

I was told by one of what would class one of the best growers on this platform to flush upwards of 3x the volume, plant count depending if you can be bothered.

Either way it works for me and the guys who do it over here, Every ones different, separates us from being sheep.
 

Emilya

Member of the Month: Mar 2019
lol, ok... well there are many many ways to approach this thing, but there are standard practices that do make things better. Do you have to flush 3x volume? Nope. The plants will adapt to whatever they find. But do you want the best plant that it could be? There are no shortcuts if this is your goal, and clearing the medium at budswell is how you excel at the end. Regarding sheep...In my goal to not be a lamb I could from now on and forever more spell SHEEP with an extra E, just to not be one... but that wouldnt make it right.
 

CC420710

Active Member
Sometimes I flush 3x the pot size until ppm levels end up at 80 the same as the tap, but the water coming out is scrapped instantly but I only do this in coco never did it yet in soil but I do just plain feed with water in soil with molasses.

I was told by one of what would class one of the best growers on this platform to flush upwards of 3x the volume, plant count depending if you can be bothered.

Either way it works for me and the guys who do it over here, Every ones different, separates us from being sheep.
This isn't about being different it's about the facts and whether or not using nutes till the end will affect taste? I am still a little confused thanks to few like you that say it does and the many that say it doesn't. So yeah still questioning whether it affects the final product or not. I do however know that feeding them nutes made them very happy so I'm torn
 

CC420710

Active Member
lol, ok... well there are many many ways to approach this thing, but there are standard practices that do make things better. Do you have to flush 3x volume? Nope. The plants will adapt to whatever they find. But do you want the best plant that it could be? There are no shortcuts if this is your goal, and clearing the medium at budswell is how you excel at the end. Regarding sheep...In my goal to not be a lamb I could from now on and forever more spell SHEEP with an extra E, just to not be one... but that wouldnt make it right.
I have a question about the final budswell you mention and when to look for it? Around a week or certain signs to look for. You say to flush 3x container flush at that phase and they continue normal feed schedule?
 

Emilya

Member of the Month: Mar 2019
Each strain is a little different, but I would go with the breeder's recommendations.. if they say this plant will bloom for 9 weeks, then on week 7, do a flush and continue on feeding and watering as you always did... but now with fresh soil and roots ready to go.
 

CC420710

Active Member
Each strain is a little different, but I would go with the breeder's recommendations.. if they say this plant will bloom for 9 weeks, then on week 7, do a flush and continue on feeding and watering as you always did... but now with fresh soil and roots ready to go.
That works out great because I did a flush start of week 7
 

bunkbudz

Well-Known Member
There was a great study going around of a Canadian company doing test results on flowers chemical composition. I wish I would’ve saved it.
They compared 3 different ways to finish the same cloned plant: fed until harvest, half nutrients till harvest, and just plain water for the last 2 weeks.
The flower had essentially the same chemical breakdown of all 3 control groups. So there’s no need to starve your plants in their final swell.
The final smell and flavor all come from a slow dry and a long cure. Oh and of course good genetics :thumb:
 

No Pain

Well-Known Member
See the word "Flush" is different when it comes to grow style Hydro -Soil . in hydroponics the salts (food) builds up in the root zone so we flush when we get into a situation of lockout/overfertilization to try and clear out the excess salts out of the root zone and depending on weather or not the root zone is comprised of fine root hairs or thick feeder roots or a combination of both depicts how long we must flush with phed water to effectively clear out the root zone (im referring to deep water culture here as coco and other systems are a tad different)

As Emilya stated the term "Flush" When it comes to soil is to remove the excess salts for the soil that surrounds the roots zone .

Now in regards to the term Flush when it comes harvest time … its starving the plants forcing them to cannibalize the food they have stored in their leaves and forces them to die out faster .

I personally do not do it as I let the plant tell me when to harvest as with all other factors being correct for growing the plant will slowly stop feeding and start to cannibalize on its own as it enters into a ripening stage this is when the leaves start to change color . You can really see this happen in deep water culture when you are monitoring the feed 24/7 with a meter.

see this flushing thing came about because people would say it taste to green ...well that's because it was to green ...it was to green and had a very green flavor and didn't burn right because the plant was not let to run its natural coarse … the bud was picked to early...have you ever had a tomato tase to green or not sweet enough that feel off the vine when you just touch it ? Now how about one that was picked and put on the table to ripen ? In both cases the plant was still being fed yet you have two very different tastes from two red tomatoes .
 

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
...all other factors being correct for growing the plant will slowly stop feeding and start to cannibalize on its own as it enters into a ripening stage this is when the leaves start to change color .
Seems like that’s what my plants do too, No Pain. So I cut the feedings back towards the end, instead of continuing to feed at full strength. Why would I? The flowers are clearly mature, and the plant is clearly winding down, and clearly feeding off of itself and managing its own needs just fine.
When I don’t cut back, the results never look nearly as good to me. Never seen any videos on the subject, just my own plants, and they always seem to tell me the same thing, but I’m going to do a side by side test next flowering round and see how the two harvests compare.


 
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