To flush or not to flush?

Indoor Growing Hydroponics
#9

This is when flushing is the right thing to do, when you want to reduce the strength of nutrients at the root surface because shit happened and there is too much. When I talk about flushing, I talk about restricting nutrients at the end of a cycle in order to improve quality as something regular and normal that is done every time. Store bought ‘flushes’ to my mind are something else and emergency plain water flushes because of shit happening are something else again (and quite necessary on occasion)

I would agree with this 100%. If you are in the UK, it is law that the water company have to supply you with a water quality analysis for free on request.

Often they just put it up on their website and have more detail than you could possibly get from a home test.

Here is one from Warrington

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#10

Your not far from me so probably similar water, think mine comes from the rivington and / or longridge reservoirs but united utilities head office is in warrington.

I keep koi carp too so have all that info :wink: @MicroDoser

Best days for water is wednesday least chlorine as they start to pump it in more starting thursday evening shift ending on sunday evening shift :wink:

Im not far from the crypto spiridium water works outbreak source :wink:

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#11

I reduce nute strength towards the end of flowering so i don’t need to do much of a flush. Usually 1 week in peat based compost and a few days in proper hydro using tap water which obviously still has some mineral content. Never saw the need for an RO flush yet but some seem to. Maybe they go nuts with additives or something eh.

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#12

Reminds me of the local chippy. Best time to get chips is when they get back from holiday because then they change the fat, hehe.

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#13

i feed fairly heavily, ~2000ppm during flower give or take a few hundred. i have 10 females of same strain from seed and i’m going to test varying levels of pre harvest flushing again. i’m also going to rerun all 10 plants a second time from clone and will flush them opposite (least flushed will become most etc). will report back in 2 months and again in 5 months.

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#14

Wow, that is indeed very heavy. Why do you go so high? I never see over 700 or so…

Please remember though, IMHO the flush is just a partial cure to remove chlorophyll so the unflushed plants will need curing or they will be harsh as a result of chlorophyll. Also note that drying too quickly can lock in that harsh taste which can make it seem that the flush is the thing that makes the flowers smoke better. If you dry too quickly then you will not see any benefit from curing and believe that the flush is what made the cannabis better, instead of the light/UV cure that happens when you deprive your plants of nutrients during the heavy growth period.

I will quote some good words from Robert Connell Clarke about drying and curing which I have found make a difference to the quality of the final product and reversed my thinking on curing and flushing.

Floral clusters will dry much
more slowly if the plant is dried whole. This means that all of the water in the
plant must pass through the stomata on the surface of the leaves and calyxes
instead of through cut stem ends. The stomata close soon after harvest and
drying is slowed since little water vapor escapes.

Usually
about 10% water remains in dry, stored Cannabis floral clusters prepared for
smoking. If some water content is not maintained, the resins will lose potency
and the clusters will disintegrate into a useless powder exposed to
decomposition by the atmosphere.

As floral clusters dry, and even after they are sealed and packaged, they
continue to cure. Curing removes the unpleasant green taste and allows the

resins and cannabinoids to finish ripening. Drying is merely the removal of water
from the floral clusters so they will be dry enough to burn. Curing takes this
process one step farther to produce tasty and psychoactive marijuana. If drying
occurs too rapidly, the green taste will be sealed into the tissues and may remain
there indefinitely. A floral cluster is not dead after harvest any more than an apple
is. Certain metabolic activities take place for some time, much like the ripening
and eventual spoiling of an apple after it is picked. During this period,
cannabinoid acids decarboxylate into the psychoactive cannabinoids and
terpenes isomerize to create new polyterpenes with tastes and aromas different
from fresh floral clusters. It is suspected that cannabinoid biosynthesis may also
continue for a short time after harvest. Taste and aroma also improve as
chlorophylls and other pigments begin to break down. When floral clusters are
dried slowly they are kept at a humidity very near that of the inside of the
stomata. Alternatively, sealing and opening bags or jars or clusters is a
procedure that keeps the humidity high within the container and allows the
periodic venting of gases given off during curing. It also exposes the clusters to
fresh air needed for proper curing.

So, for unflushed plants which still contain all of their “chlorophylls and other pigments” it is important to dry them slowly, and cure them properly retaining some moisture to allow biological processes to continue. Then, even with no flush (although if you feed that heavily you may need a much longer cure) you should get “tasty and psychoactive marijuana.”.

I would say the minimum time to cure would be at least two or three times as long as the plants were flushed or 4 weeks or so.

Nice one for doing this test, Myself I am sure of my own results which have made me stop flushing but I am very interested in seeing how other people do.

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Properly flushed final product
#15

Measured radioactivity of popular nutrients.


I think I’ll continue flushing my hydro.

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#16

You do whatever you like. As will I.

EDIT : Your linked site actually has a bit on flushing,the-flushing-cannabis-myth-busted, I have no idea why you did not link to that instead of whatever you were trying to show by talking about organic vs hydro…

It says “flushing had no effect on reducing tissue nutrient accumulation between flushed crops and control (a crop that wasn’t flushed)” confirming my position.

One thing that you could have linked to which does contradict what I thought is that flushing did not reduce yields. They say it did not have a positive nor a negative effect on quality, which seems right if yield was not affected.

Your link confirms my position that flushing does not remove anything and is instead effectively a partial light cure and the only way to get smooth smoking weed is through a cure, either before you cut the plant, or afterwards.

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#17

Everyone’s garden and technique is different. I personally never exceed 1.4EC but I know others who regularly feed over 2.0EC

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#18

Enjoy your polonium gaggers :+1:

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#19

flushing myth.png1619×587 71.3 KB

From your link.

Flush or do not, it does not do anything but if it makes you happy, then do whatever you like. Personally, I like to present facts to others so they can make better informed decisions.

Turn around clockwise three times, click alternate fingers 15 times, starting with the left hand of course, then jump up and down and say “bibble” before you cut your plant if you want, it will have the same effect.

None. Because it is superstition that is not based in fact.

Again, I ask what have I done to you to cause you to act like this?

You are not making yourself look good lately.

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#20

I just like getting you all heatered up.

My point actually was that nutrient solution contains radioactive compounds.

Plants are still respiring in the final 2-3 weeks, and they are also mostly water or in your case solution by weight when harvested. You can harvest them full of water, or you can harvest them full of (albeit mildly) radioactive solution. I’m simply proposing to you that polonium, etc doesn’t “cure out”.

Label a jar of your stuff “Un-flushed Hydro”, take it to the dispensary, and see how fast it sells.

You’ve never proposed any benefit to watering nutrients in the final week. Please enlighten me.

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#21

Thanks for the info. Definitely makes me want to look more into it. I usually wait until first sign of Amber and flush for 10 days.

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#22

My flush started two days ago with 30mL Sugar Daddy and CalMag 2.5mL per gallon, every plant gets like one and a half quarts. Will be ready in about 13-15 days i think. Doing the flush every other day and will continue until 30% of trichomes have gone 100% amber… Even if there are new trichomes coming out at the moment.

Might do the 48 hours of darkness right before cutting! Dunno.

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#23

Gonna back up @MicroDoser here @Scissor-Hanz guess you didn’t actually read like a good 80% of the article you posted.

Specifically in relation to radiation claims of organic or in organic and how in radiations is present everywhere, and how said initial study was flawed and mis-accurately represented values in almost an apple vs orange type way.

If i could cut and paste from the site i would, but it would also be a wall of text.

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#24

No problem, but maybe you can explain to me ANY benefit of using nutrient solution right up until harvest, since he has avoided the question for months?

Even if the final product is similar(it’s not, imo), in the least you are pouring cash down the drain.

…and you are correct, I was reading about hydro vs organic and I hadn’t finished 1/4 of the article when I came across the nutrient radioactivity chart and thought it might be worthy of discussion. MY APOLOGIES.

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#25

I believe the benefits they’re suggesting is denser, more nutrient rich final product.

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#26

Naturally or at least in my observation our plants when nearing the end of their life cycles shut down there uptake anyways, as they start to rely on previously stored nutrients as its easier for them to utilize stored components than uptaking new.

So will i say feeding heavy right till the end is a benefit, no because the plant doesn’t need it, but at the same time cutting all feed off early and forcing plants to go to those stores is also not a benefit as your cutting things short “unless that is your desire”. The plant will still uptake what it needs, its just in the final stages it severely reduced.

So the counter argument to me is neither feeding heavy beneficial or flushing actually ideal, and the plant tapers off anyways. We match what the plant wants unless we are trying to force something.

Btw my comment was in relation to radioactive elements, which btw Carbon is radioacitve if we’re gonna generalize…

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#27

Is there a way to deduct that we all irradiate somehow, being carbon life forms!?

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#28

So you are using you own personal anecdotal evidence and hypothesis, same as me.

There is quite a difference in halflife between carbon and polonium radioactivity. As I’m sure you know.

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