When to Start My Flush?

1212ham

Well-Known Member
Canna feed charts drop the bloom mix in the last week or two, only Boost and Cannazym

View attachment 5204082
That chart never mentions flushing. ;-)

Here's what Canna says about flushing.

FLUSHING: A MIRACLE CURE OR MERELY WISHFUL THINKING?
Figure 7: Knowing these waypoints in your plants life cycle will help you
grow the best crops. Plants give many clues how they are processing.
FlushingNowadays, information on growing and plant-related problems comes in all sizes and colors, thanks to the Internet and
its panoply of forums where gurus generously offer their wisdom to help troubled souls.
Of the many cures instantly offered by those online shamans is the famous “flush it well!” By that, gurus mean that the
growers should “wash” their growing medium with copious amounts of water, with the goal being to restore balance,
magically sweep all poisons out and with the help of faith make everything great again.
How good is it?

Is it really something useful? Does it really set everything right again and solve problems?
What if the grower’s problem is not related to a “nutrient lock out” (another famous term used by the gurus) or a heavy salt
build-up and the grower flushes everything out of the medium? Would it really help the plant to be nutrient deprived for
an extra few days? How would you feel if you were sick from starvation and the doctor said “I don’t need to check anything,
drink plenty of water, avoid food for the next few days and you’ll be fine!”? Of course, this doesn’t make any sense for
plants either.

Reasons
On the other hand, it may be necessary to fix a salt build-up issue because they do tend to happen. This issue can be the
result of numerous causes, the main ones being high temperatures, excessively dry air, too much wind and lights that are
too close to the canopy.
First, the grower needs to assess if a high salt level is really the problem, and for this a growing medium test is essential.
You can find out how to do this here: http://www.cannagardening.com/measuring_coco. While the article is about coco,
the same method also works for a peat-based medium. Rockwool growers do have an easier time, as all they need to do is
extract the solution with a big syringe and measure the salt levels.
If the salts levels are off the chart, is a copious shower of water through the medium a good idea? Yes! But how efficient is
a shower without soap?

Efficient
A flush is always more efficient when it is done with some nutrients; they act a bit like soap, grabbing salts as they go
through. Use half of the usual nutrient dose, water through the containers, repeating several times, making sure there is
plenty of runoff. Measuring runoff at the end could help you assess if the amount of solution you poured in is sufficient. Not
only will it “clean” the medium in a more efficient way, it will also leave behind some fresh nutrients to prevent your plant
from starving until the next feed.
Another problem that comes with plain water flushes is that they affect the medium’s chemistry and content. If we look at
coco, plain water will leach the nutrient buffer out, possibly leading to calcium and magnesium deficiency and the release
of excess potassium. In the case of peat-based mix, the lime that keeps the pH where it needs to be might get pushed out.
This would bring the medium closer to peat’s natural pH of 4.4-5.0, a level that many plants aren’t too happy with.
Take your time
Keep in mind that plants do not like drastic changes in anything. If the plants have been used to very high salt levels and
suddenly these levels drop quickly, you might see some other problems show up later. Always take care to prevent the salt
build-up by watering properly, with plenty of runoff at each feed. Take your time, measure your parameters and enjoy a
much easier, healthier growth. This will also ensure that you never have to consult the clairvoyance of the online ‘master
growers’. Good luck and happy gardening![/QUOTE]
 

bubblescrogs

Well-Known Member
That chart never mentions flushing. ;-)

Here's what Canna says about flushing.

FLUSHING: A MIRACLE CURE OR MERELY WISHFUL THINKING?
Figure 7: Knowing these waypoints in your plants life cycle will help you
grow the best crops. Plants give many clues how they are processing.
FlushingNowadays, information on growing and plant-related problems comes in all sizes and colors, thanks to the Internet and
its panoply of forums where gurus generously offer their wisdom to help troubled souls.
Of the many cures instantly offered by those online shamans is the famous “flush it well!” By that, gurus mean that the
growers should “wash” their growing medium with copious amounts of water, with the goal being to restore balance,
magically sweep all poisons out and with the help of faith make everything great again.
How good is it?

Is it really something useful? Does it really set everything right again and solve problems?
What if the grower’s problem is not related to a “nutrient lock out” (another famous term used by the gurus) or a heavy salt
build-up and the grower flushes everything out of the medium? Would it really help the plant to be nutrient deprived for
an extra few days? How would you feel if you were sick from starvation and the doctor said “I don’t need to check anything,
drink plenty of water, avoid food for the next few days and you’ll be fine!”? Of course, this doesn’t make any sense for
plants either.

Reasons
On the other hand, it may be necessary to fix a salt build-up issue because they do tend to happen. This issue can be the
result of numerous causes, the main ones being high temperatures, excessively dry air, too much wind and lights that are
too close to the canopy.
First, the grower needs to assess if a high salt level is really the problem, and for this a growing medium test is essential.
You can find out how to do this here: http://www.cannagardening.com/measuring_coco. While the article is about coco,
the same method also works for a peat-based medium. Rockwool growers do have an easier time, as all they need to do is
extract the solution with a big syringe and measure the salt levels.
If the salts levels are off the chart, is a copious shower of water through the medium a good idea? Yes! But how efficient is
a shower without soap?

Efficient
A flush is always more efficient when it is done with some nutrients; they act a bit like soap, grabbing salts as they go
through. Use half of the usual nutrient dose, water through the containers, repeating several times, making sure there is
plenty of runoff. Measuring runoff at the end could help you assess if the amount of solution you poured in is sufficient. Not
only will it “clean” the medium in a more efficient way, it will also leave behind some fresh nutrients to prevent your plant
from starving until the next feed.
Another problem that comes with plain water flushes is that they affect the medium’s chemistry and content. If we look at
coco, plain water will leach the nutrient buffer out, possibly leading to calcium and magnesium deficiency and the release
of excess potassium. In the case of peat-based mix, the lime that keeps the pH where it needs to be might get pushed out.
This would bring the medium closer to peat’s natural pH of 4.4-5.0, a level that many plants aren’t too happy with.
Take your time
Keep in mind that plants do not like drastic changes in anything. If the plants have been used to very high salt levels and
suddenly these levels drop quickly, you might see some other problems show up later. Always take care to prevent the salt
build-up by watering properly, with plenty of runoff at each feed. Take your time, measure your parameters and enjoy a
much easier, healthier growth. This will also ensure that you never have to consult the clairvoyance of the online ‘master
growers’. Good luck and happy gardening!
[/QUOTE]
It mentions dropping the bloom nutrients completely for the last week or two. Your quote was from a 2019 article about coco/soil. This is what they currently say https://www.canna.com.au/flushing

Maybe it's different in the southern hemisphere because the toilet water swirls the other way


Checklist: 24 hour flush
  • Remove nutrient solution from the reservoir and clean the container and pipes system as much as possible.
  • Pour water through the system to flush through unwanted salts etc. and remove.
  • Fill the reservoir with plain water or flush solution.
  • Test and correct the pH level.
  • Leave to circulate for 24 hours.
  • Remove plain water or flush solution from the reservoir.
  • Replace with fresh nutrient solution.
Checklist: harvest flush
  • In the final two or three weeks before harvest gradually reduce the nutrient strength, by checking the conductivity level.
  • One week before harvest remove the nutrient solution from the reservoir.
  • Replace with plain water or flush solution.
  • Test and correct the pH level.
  • Leave to circulate until harvest.
 

1212ham

Well-Known Member
Last edited:
It mentions dropping the bloom nutrients completely for the last week or two. Your quote was from a 2019 article about coco/soil. This is what they currently say https://www.canna.com.au/flushing

Maybe it's different in the southern hemisphere because the toilet water swirls the other way
Maybe it's Canna trying to sell you Canna Flush.

As I said, it has been discussed here ad nauseam.

[/QUOTE]
I just quick dried a bud in the microwave and smoked a joint and the ash was very black. Will report back on ash colour after my 6 week flush.
 

bubblescrogs

Well-Known Member
Maybe it's Canna trying to sell you Canna Flush.

As I said, it has been discussed here ad nauseam.

I just quick dried a bud in the microwave and smoked a joint and the ash was very black. Will report back on ash colour after my 6 week flush.
[/QUOTE]
Their article says plain water is fine but some people like their flush. Doesn’t seem that much of a strong arm tactic to me but I’m all out of foil for my hat
 
@bk78 I’ve been doing the recommended 10-15 gallons per day and my plants are starting to seem droopy. Could this mean they are ready for harvest at only 5.5 weeks ?
 
Top