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Flushing: A Tutorial by Papa Green

Mr. Krip

Grow Journalist
420 Staff
I believe the Clearex is only for a short period flush (15-60 minutes). That's what their website said anyway ;)

As I understand the theory,the final flush is to remove the chemicals and elements that accumulated by adverse selection and/or from compounding.

Essentially, the leftovers that were either held in reserve by the plant for later use, or that were provided to the plant in excess quantity that the plant didn't spend the energy to dispose of, or the salts and such that remain behind.

So if your clearex step aides in unlocking, and there are no new nutes present to be used, the plant turns on itself and consumes those stores that's it's held in reserve.

I hope others jump in here because I qualify I'm offering opinions that I've formed from research; I'm sure there are people here far more experienced that I that can confirm or correct my comments.

That said, I think the choice you face is to starve your plants those last 4-7 days (DWC with nothing but pure water), which will surely help ensure that any residual nutrients that might remain are fully minimized, or add a carbo type product like bud candy or sweet leaf to provide an easily digestible non-chemical energy supply during the last phase on the plants life.

Like everything in life it's a tradeoff. With pure water, you'll more easily rid the built up nutrients but might not maximize swell. With carb supplements you'll maximize swelling but might not get rid of the last few points of residuals.
Soniq, thanks again! Your research on flushing coincides with mine and the 15-60 minutes does sound about right, especially when considering the first post of this thread. :thanks:
 

Retired Seven

New Member
Soniq there is no need at all for anyone to chime in here! Once again that explanation, in my experience and opinion, would say there is no better way to put it. Good Job as usual!
 
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The303Stoner

New Member
Nice easy way to sticky sweet and clean smoke. I used this pre harvest method I used for soil Fox farm Sledgehammer (as labeled) with 1 tea spoon 5ml. of Humboldt nutrients ES honey and 1 table spoon 15 ml. Fox Farm Big Bloom per gal.. I used all three and let dry than I used Es honey and Big Bloom let the pots dry out and cut them babies.(in soil) I also use a ph drop to 6 to get late finishers caught up lower for hydro. Stay away from nutes with kelp near harvest flush extra good it can leave a bad taste.
 
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Keith Lake

Human Resources
420 Staff
fish4250 said:
he/she MEANS keep it i laymen terms? right
In essence...

The grower uses nutrients (nutes) to help the plant grow. Whether in the water or in the soil the grower is supplying excess chemicals to the plant.

The plant uses up what it needs but leaves behind a lot of chemical compounds that it doesn't want.

If these chemicals are not "flushed away" you end up smoking them. They taste like crap and can crackle and pop and stink in worst case. No one wants to smoke chemicals.

During the last week or so of the plant's life, the connoisseur grower will withhold the nutrients (except for maybe a little sugar) to force the plant to use up the excess nutes. They flush the plant with just water to dilute away the chemicals. By flush we mean pour water through the soil or change the hydro bath to pure water.

Commercial brick growers don't go to all this trouble and this is one primary reason that properly flushed (and cured) homegrown is far superior in taste.
 

Ganjahoarder

New Member
I was planning on doing this tomorrow. I was a little hesitant as I had never done it b4....this article has helped me tremendously. Thanks
 

mudrunner

New Member
this was awesome man! im not even close to this stage yet but I still read through the whole thread lol. very simple and straight forward.... BOOKMARK!

:adore:
 

Keith Lake

Human Resources
420 Staff
mudrunner said:
this was awesome man! im not even close to this stage yet but I still read through the whole thread lol. very simple and straight forward.... BOOKMARK!

:adore:
If you like this one, suggest you take a look at the "how to grow..." link in my sig, and spend some quality time reviewing the dry and cure methods. It's great to get the chemicals removed, it's another to manage the chlorophyll degradation process perfectly. Both are required for optimal results.
 

first-tymer

New Member
Hey guys, I'm new to this thread, but I like the fact that there isn't a lot of patting each other on the back and small talk... Too many journals/how to threads are littered with whitty banter and fake high fives. This just makes it hard to find the info you are looking for cause you have to scroll through all that b.s. first just to find it three pages from where you started.

Anyway, I have a question reguarding flushing a waterfarm hydroponic drip/DWC system... I am using hydroton as my primary medium, but when I started my seedling I did so using a rapid rooter. When I transplanted the plant into the hydroton I did so by putting the rapid rooter as deep into the hydroton as I could to counter act the stretching that occured early in the plants growth. I understand the concept behind flushing, I'm worried about the rapid rooter soaking up too much water and rotting the stem/roots deep down into the hydroton at the rapid rooter because I;m afraid the rapid rooter wont be able to dry itself out correctly. I also may be overthinking this whole process! I've been known for that as well. I may just be scared now that I am approaching the end of the grow and I don't wanna mess it up now.
 

Keith Lake

Human Resources
420 Staff
first-tymer said:
Hey guys, I'm new to this thread, but I like the fact that there isn't a lot of patting each other on the back and small talk... Too many journals/how to threads are littered with whitty banter and fake high fives. This just makes it hard to find the info you are looking for cause you have to scroll through all that b.s. first just to find it three pages from where you started.

Anyway, I have a question reguarding flushing a waterfarm hydroponic drip/DWC system... I am using hydroton as my primary medium, but when I started my seedling I did so using a rapid rooter. When I transplanted the plant into the hydroton I did so by putting the rapid rooter as deep into the hydroton as I could to counter act the stretching that occured early in the plants growth. I understand the concept behind flushing, I'm worried about the rapid rooter soaking up too much water and rotting the stem/roots deep down into the hydroton at the rapid rooter because I;m afraid the rapid rooter wont be able to dry itself out correctly. I also may be overthinking this whole process! I've been known for that as well. I may just be scared now that I am approaching the end of the grow and I don't wanna mess it up now.
You might check out the how to grow forum (link in my signature). These are segmented by specific topic with little off topic banter. Journals tend to be more interactive and a chance for friends to interact ;)
 

first-tymer

New Member
You might check out the how to grow forum (link in my signature). These are segmented by specific topic with little off topic banter. Journals tend to be more interactive and a chance for friends to interact ;)
I looked there, but could find no answer to my question... The question is a little too specific for that general of a forum. Hard to find anyone that is going about things like I am, which in turn makes it hard for me to get accurate answers to my questions. I am already aware of how to flush in a waterfarm system, need to figure out how it will work with a rapid rooter in the bottom like mine...
 

direless

Member
Would it be possible to cut the plant and place it in clean h2o, like a flower in a vase, for a couple days to acheive the same results. I would think you could still also use clearex or some other similar product.

My understanding is that by running clear h20 the osmotic pressure leans toward the fresh h2o, particles want to balance on both sides of the plant cell walls which then leaches out unused salts. Not exactly sure how the flushing products work but assume they an unbalanced osmotic pressure

I run a 50 gal RO res and draining and refilling gets to be a hassle, not to mention plants seem to mature at different rates.
 

bl8ant

New Member


The WHAT, WHEN, WHY and HOW to Flush Your Plants


I know when I started growing, I had never heard of "Flushing", then I heard a lot about flushing and it was confusing. Even some warnings not to flush.

So, for new growers out there, here's the What, When, Why and How to Flush your Cannabis plants.

First the WHAT and WHY:

Many folks think flushing is about cleaning out the plants. In an indirect way this is true, but its really much more about your soil and roots and res. When you flush the plants, you are running large amounts of water through the system. Sometimes you will add something to that water to assist - more on this below.

So what exactly happens that you might want to flush? Lets look at the way the plant takes up nutes. Lets use an imaginary nute that has 3 minerals the plant wants : A,B,C. When you buy this nute they know the plant is not going to want the same amount of everything so they balance it for you and put in 10 units of A, 5 units of B, and 1 unit of C.

When you use the nute - the plant loves you for it. You see immediate results. You say to yourself this stuff is giving the plant exactly what it wants. This is unlikely. What is probably happening is that the plant is using what it needs from the nutes, but there is likely some that is not being used as much as others.

So after 3 days your plant may have only used 8/10 units of A while having used up all the B and C minerals. So you look at them, and your ppm meter says feed them - so you add more nutes. Now you have the same original mix of B and C, but there is still A left from before and you've just added more.

So, again, the plant takes what it needs. 8 units of the A and all the B and C. Now you have again used all the B and C, but there are 4 units of A remaining in the soil or res.

This would not be a bad thing if the plant could continue to operate this way. Just make sure she has more than she wants, let her take what she needs and its easy right? Unfortunately - its a little more complicated than that.

What happens is that certain minerals interact with other minerals. And when they are in balance you get good consistent growth. But if they are out of balance you will see a deficiency. What is important to understand here is that the deficiency may not be caused by a LACK of one mineral - but an OVER-ABUNDANCE of another. Its odd to think that putting in too much of one will limit another, but this is what's known as "Nutrient Lockout". It is much more prevalent in Salt-Based nutrients but can affect anyone.

Just changing the res every 7-10 days is a great way to sort of reset these imbalances. You've likely seen PitViper's magnificent work - he is religious about changing his res every week.

So experienced indoor gardeners (check out LabRat420 - he hasn't even changed the res in 80+ days as of this writing, let alone a flush, and his colas are thicker than beer cans) can get away with much less flushing because they know how to balance the nutes individually. Outdoor in-the-ground plants are even luckier. Mother Nature is taking care of the flush for them with a crazy thing she does called rain.

The WHEN:

For the rest of us, there are some times when its good to flush. Both McBudz and ---------- include a flush in their schedule and they are Grow Support. Both of their journals are clinics in proper technique.

Like all things in growing - too much of a good thing is bad. And too much flushing is not only a waste of time and money, but you can flush away stuff that can be good for the plants.

There are three basic times/reasons to flush:
1. Pre-Harvest Flush
- many folks agree that this will improve the flavor of the cured bud. If you're using Clearex then you can flush as close as 3 days before harvest. Other methods should be done a week to 10 days before harvest and repeated three days later.

2. When you dramatically change the nutrient schedule - usually when you start Flowering, some flush entering Veg as well. This is a preventative flush. Again - not mandatory, but not a bad idea. Also, in soil, this is about the time the plants have sucked all the nutes from the soil, And before you go jacking it up with your own mix - its not a bad idea to sort of zero it out.

3. If you are experiencing Nutrient Lockout. Usually (NOT ALWAYS!) when you have a dramatic nutrient imbalance the cure is not to try to figure out the exact one, but flush the plants, and add a fresh WELL BALANCED and MEDIUM STRENGTH dose of nutes. Now don't go flushing at every burned leaf or tinge of yellow. Use common sense. But if you see dramatic problems, and there are no obvious signs of another problem like heat, cold, grey goop in the res, root rot, etc - then its prolly not a bad idea to flush the plants and re-fill the res.

Now that you understand the WHAT, WHY and WHEN of flushing - let's talk turkey and get to the HOW.

I have experience with the 3 basic techniques: Plain Water, Water with extremely low nutes, and Clearex - there is a time and place for all of them and the method is basically the same. And remember if you have plants in multiple containers - feel free to experiment with multiple methods on the same grow.

I use Clearex and will describe that method in detail. Clearex is a brand name flush from Botanicare. Many folks use plain water or a very, very mild nutrient/water mix just as effectively. I won't try to make a suggestion on ppm for what a very light mix is, but let me tell a quick story to illustrate.

I had 5 plants in 5G soil that were ready for harvest. I thought. 4 plants did indeed finish in the next 4 or 5 days after the Clearex flush and it was perfect. They tasted great after an 8 day dry and 2 week cure.

The fifth plant, however, was not quite finished. So I decided to give it one more feeding, then wait three days, then flush again using the low ppm method as a test. All the plants had been receiving about 1250ppm the week before. So I fed this one 750ppm with very little runoff. Then three days later I gave it 100ppm with about 50% runoff. Then 4 days later I gave it plain water with about 50% runoff. Then 3 days later I cut it. So the timeline at the end was: Wed - Clearex 5 plants; Sun - Chop 4, feed 1 750; Thurs - feed 100; Sunday - plain water; Wed - Chop. This was wrong. I had not allowed enough time at the end, nor used enough plain water.

I dried that plant exactly the same 8-10 days as the others - 'til her stems snapped fine, then the cure. After a two week cure the smoke was still extremely harsh on the exhale, and the buds crackled when burned. BTW - this is the sure sign of a bad cure or flush - if the smoke tastes fine on the way in but becomes ridiculously harsh on the way out. So I put that bud back in to cure and left it for the last to be smoked. six weeks of curing later - for a total of TWO MONTHS OF CURING - it was still snap, crackle pop and tasted harsh. So I can't give you an estimate on what low ppm means, but I can tell you what I did was NOT enough of a flush. Perhaps someone who uses the low ppm method effectively can add to this. Now back to our regularly scheduled program with a method that I have had 100% success with.

HOW TO:

Remember - when you are flushing, you are trying to get rid of that buildup of nutrients. Most of that buildup is NOT above the ground. You are trying to flush the roots and soil. So try to do it at the beginning or end of the day when you can mist the plants with plain water. This will lower their transpiration and keep them from sucking up more flush water than they need. This step is not required, but its on the Clearex label so I do it.

Step 1 - Drain your res and refill. Add Clearex at about 20-30ml / Gallon. pH balance to 5.7-6.2 depending on whether you're hydro or soil.

Step 2 - Run this mix through your plants. If you are doing containers you want to achieve significant runoff. Far more than your standard watering. The bottle calls for AT LEAST 80-90% runoff. So if you have a 5 gallon pot, you will want to put 3-6 Gallons of water through depending on how dry the soil is when you flush, and how much drainage. With a little experience with your soil you can skip the rest of the steps and call it done right there. If you really want to be sure then use the ppm measuring described below.

If you are doing hydro, saturate the system for 5-15 minutes then allow it to drain back to the res. No need to drain the res.

Step 3 - Measure the ppm of the runoff.

Step 4 - Run the same Clearex/water through again.

Step 5 - Again measure the ppm of the runoff. The ppm should be the same or higher than the first time. This is because you are sucking all those excess nutes out.

Step 6 - Keep repeating this cycle until you see little to no change on the ppm. For me this is usually two times, sometimes three.

That's it!

Now drain the res again. Refill with your regularly scheduled nutes or water and let the timer do its thing.

I hope this helps.

Keep on Growin!!



Good afternoon Papa Green .... i have 5 plants in 4gallon pots ( 15"x10" ) , that seem to be experiencing different phases of Nute Lockout... they began as seedlings in early March and now are just beginning to show signs of blooming... I have been using Bio Bizz organics during the mid veg stage and for the last month, since July, i have been using Bio Bloom ...all is well but they seem slow to actually flower so i am regulating the darkness and keeping them much darker from 9pm till 8am...i hope that works.

They are all growing on a small balcony outdoors and get direct sunshine all morning and afternoon... i have decided to leave them on the backside and now they miss the early sun but they are getting to big to move around anymore :)

The reason i suspected nute lockout was also because the leaves of the Amnesia are curled and wiry when sprouting and some of the fan leaves began to get brown along the spikes nothing radical but i flushed anyway... I flushed with about 30 liters of fresh water for each plant and collected the runoff with little loss in volume until it was almost clear.... so now...i was wondering... should i continue to just water with clean water for 2 weeks even tho they are not really flowering ? or should i begin to gently add the BIO Bloom nutes... in the next watering...and it rained lots last night :)

I have a Skywalker Kush, OG Kush (which is now *BG Kush ) Amnesia haze, Chemdawg, and some other hybrid sativa that i still can't identify yet.




*BG = Balcony Grown :p
 
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BackwoodsBabe

New Member
:cheer:
thanks for the info....i use soil and my ph is stuck at 7.5!!!!!!! ive done the peat moss thing...but no help....plz someone help....could i flush?she isin flower mode....ima noob.
 

420romeo

New Member


The WHAT, WHEN, WHY and HOW to Flush Your Plants


I know when I started growing, I had never heard of "Flushing", then I heard a lot about flushing and it was confusing. Even some warnings not to flush.

So, for new growers out there, here's the What, When, Why and How to Flush your Cannabis plants.

First the WHAT and WHY:

Many folks think flushing is about cleaning out the plants. In an indirect way this is true, but its really much more about your soil and roots and res. When you flush the plants, you are running large amounts of water through the system. Sometimes you will add something to that water to assist - more on this below.

So what exactly happens that you might want to flush? Lets look at the way the plant takes up nutes. Lets use an imaginary nute that has 3 minerals the plant wants : A,B,C. When you buy this nute they know the plant is not going to want the same amount of everything so they balance it for you and put in 10 units of A, 5 units of B, and 1 unit of C.

When you use the nute - the plant loves you for it. You see immediate results. You say to yourself this stuff is giving the plant exactly what it wants. This is unlikely. What is probably happening is that the plant is using what it needs from the nutes, but there is likely some that is not being used as much as others.

So after 3 days your plant may have only used 8/10 units of A while having used up all the B and C minerals. So you look at them, and your ppm meter says feed them - so you add more nutes. Now you have the same original mix of B and C, but there is still A left from before and you've just added more.

So, again, the plant takes what it needs. 8 units of the A and all the B and C. Now you have again used all the B and C, but there are 4 units of A remaining in the soil or res.

This would not be a bad thing if the plant could continue to operate this way. Just make sure she has more than she wants, let her take what she needs and its easy right? Unfortunately - its a little more complicated than that.

What happens is that certain minerals interact with other minerals. And when they are in balance you get good consistent growth. But if they are out of balance you will see a deficiency. What is important to understand here is that the deficiency may not be caused by a LACK of one mineral - but an OVER-ABUNDANCE of another. Its odd to think that putting in too much of one will limit another, but this is what's known as "Nutrient Lockout". It is much more prevalent in Salt-Based nutrients but can affect anyone.

Just changing the res every 7-10 days is a great way to sort of reset these imbalances. You've likely seen PitViper's magnificent work - he is religious about changing his res every week.

So experienced indoor gardeners (check out LabRat420 - he hasn't even changed the res in 80+ days as of this writing, let alone a flush, and his colas are thicker than beer cans) can get away with much less flushing because they know how to balance the nutes individually. Outdoor in-the-ground plants are even luckier. Mother Nature is taking care of the flush for them with a crazy thing she does called rain.

The WHEN:

For the rest of us, there are some times when its good to flush. Both McBudz and ---------- include a flush in their schedule and they are Grow Support. Both of their journals are clinics in proper technique.

Like all things in growing - too much of a good thing is bad. And too much flushing is not only a waste of time and money, but you can flush away stuff that can be good for the plants.

There are three basic times/reasons to flush:
1. Pre-Harvest Flush
- many folks agree that this will improve the flavor of the cured bud. If you're using Clearex then you can flush as close as 3 days before harvest. Other methods should be done a week to 10 days before harvest and repeated three days later.

2. When you dramatically change the nutrient schedule - usually when you start Flowering, some flush entering Veg as well. This is a preventative flush. Again - not mandatory, but not a bad idea. Also, in soil, this is about the time the plants have sucked all the nutes from the soil, And before you go jacking it up with your own mix - its not a bad idea to sort of zero it out.

3. If you are experiencing Nutrient Lockout. Usually (NOT ALWAYS!) when you have a dramatic nutrient imbalance the cure is not to try to figure out the exact one, but flush the plants, and add a fresh WELL BALANCED and MEDIUM STRENGTH dose of nutes. Now don't go flushing at every burned leaf or tinge of yellow. Use common sense. But if you see dramatic problems, and there are no obvious signs of another problem like heat, cold, grey goop in the res, root rot, etc - then its prolly not a bad idea to flush the plants and re-fill the res.

Now that you understand the WHAT, WHY and WHEN of flushing - let's talk turkey and get to the HOW.

I have experience with the 3 basic techniques: Plain Water, Water with extremely low nutes, and Clearex - there is a time and place for all of them and the method is basically the same. And remember if you have plants in multiple containers - feel free to experiment with multiple methods on the same grow.

I use Clearex and will describe that method in detail. Clearex is a brand name flush from Botanicare. Many folks use plain water or a very, very mild nutrient/water mix just as effectively. I won't try to make a suggestion on ppm for what a very light mix is, but let me tell a quick story to illustrate.

I had 5 plants in 5G soil that were ready for harvest. I thought. 4 plants did indeed finish in the next 4 or 5 days after the Clearex flush and it was perfect. They tasted great after an 8 day dry and 2 week cure.

The fifth plant, however, was not quite finished. So I decided to give it one more feeding, then wait three days, then flush again using the low ppm method as a test. All the plants had been receiving about 1250ppm the week before. So I fed this one 750ppm with very little runoff. Then three days later I gave it 100ppm with about 50% runoff. Then 4 days later I gave it plain water with about 50% runoff. Then 3 days later I cut it. So the timeline at the end was: Wed - Clearex 5 plants; Sun - Chop 4, feed 1 750; Thurs - feed 100; Sunday - plain water; Wed - Chop. This was wrong. I had not allowed enough time at the end, nor used enough plain water.

I dried that plant exactly the same 8-10 days as the others - 'til her stems snapped fine, then the cure. After a two week cure the smoke was still extremely harsh on the exhale, and the buds crackled when burned. BTW - this is the sure sign of a bad cure or flush - if the smoke tastes fine on the way in but becomes ridiculously harsh on the way out. So I put that bud back in to cure and left it for the last to be smoked. six weeks of curing later - for a total of TWO MONTHS OF CURING - it was still snap, crackle pop and tasted harsh. So I can't give you an estimate on what low ppm means, but I can tell you what I did was NOT enough of a flush. Perhaps someone who uses the low ppm method effectively can add to this. Now back to our regularly scheduled program with a method that I have had 100% success with.

HOW TO:

Remember - when you are flushing, you are trying to get rid of that buildup of nutrients. Most of that buildup is NOT above the ground. You are trying to flush the roots and soil. So try to do it at the beginning or end of the day when you can mist the plants with plain water. This will lower their transpiration and keep them from sucking up more flush water than they need. This step is not required, but its on the Clearex label so I do it.

Step 1 - Drain your res and refill. Add Clearex at about 20-30ml / Gallon. pH balance to 5.7-6.2 depending on whether you're hydro or soil.

Step 2 - Run this mix through your plants. If you are doing containers you want to achieve significant runoff. Far more than your standard watering. The bottle calls for AT LEAST 80-90% runoff. So if you have a 5 gallon pot, you will want to put 3-6 Gallons of water through depending on how dry the soil is when you flush, and how much drainage. With a little experience with your soil you can skip the rest of the steps and call it done right there. If you really want to be sure then use the ppm measuring described below.

If you are doing hydro, saturate the system for 5-15 minutes then allow it to drain back to the res. No need to drain the res.

Step 3 - Measure the ppm of the runoff.

Step 4 - Run the same Clearex/water through again.

Step 5 - Again measure the ppm of the runoff. The ppm should be the same or higher than the first time. This is because you are sucking all those excess nutes out.

Step 6 - Keep repeating this cycle until you see little to no change on the ppm. For me this is usually two times, sometimes three.

That's it!

Now drain the res again. Refill with your regularly scheduled nutes or water and let the timer do its thing.

I hope this helps.

Keep on Growin!!



What about for outdoor growers like me? How do I flush them then assuming I use regular water? When? How many times? Still confused! ?
 
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