Flushing

[00bladerunner]

Just curious as to how people growing with a soilless medium are flushing before harvest.
I've always done about a 10-14 day flush. I usually go by tasting the leaf stems for bitterness and it usually works out great for me. But I'm growing a more sativa dominant plant then I normally grow which I'm going to cut at about 70 days from what I'm seeing so far. So I've got about 4 days left. I usually don't check runoff ppm but have been experimenting with it a bit this time. I flushed tonight....I grow in 3 gallon pots. So tonight I put 5 gallons of water through each one and checked runoff. They were still showing 700-800PPM in the runoff after 5 gallons, but chewing the leaves is showing no bitter taste, they actually taste pretty good. Seems a bit high to me, but cant taste any bitterness.
Does anybody do runoff checks?? And what do you look for as a ppm number before chopping.

 

[Douglas.Curtis]

Taste is subjective. 3/4ths of the population have "up to" an average ability to taste and smell. I prefer 300ppm or less in the root zone near harvest time. Personally, I slowly fade the available nutrients the last few weeks. Since I'm in DWC, the "flush" for me is changing out the res with pure r/o. Within 5 days I see around 300ppm, sometimes a bit more and I harvest.

Everyone is different.

 

[mexweed]

my plants are in 5 gallon when they finish, the last 4 weeks are just water, 1st week until runoff, 2nd week 5 gallons, 3rd week 10 gallons, 4th week 15 gallons, so by the end of it I have ran 6x's the container size of water through it

 

[Douglas.Curtis]

my plants are in 5 gallon when they finish, the last 4 weeks are just water, 1st week until runoff, 2nd week 5 gallons, 3rd week 10 gallons, 4th week 15 gallons, so by the end of it I have ran 6x's the container size of water through it

This is close to the same output, depending on your soil composition. My concern would be to make sure they dry out quickly enough.


I can imagine it's rather smooth smoking.

 

[~SpacedCWBY~]

I use a flush formula from cyco nutrients. Just add it to the water the last 2 weeks. No hard flushing required. I've always been a proponent of good hard flushing until I found this stuff. So much less work.

 

[wutwut]

my plants are in 5 gallon when they finish, the last 4 weeks are just water, 1st week until runoff, 2nd week 5 gallons, 3rd week 10 gallons, 4th week 15 gallons, so by the end of it I have ran 6x's the container size of water through it

have you noticed lower yields?

 

[mexweed]

this is my first time growing these strains and doing this type of grow so nothing to compare it to yield wise, but I would have to say this is one of my best grows

they are top dressed at week 4 and fed a strong tea at week 5, week 6 is the plain water until runoff and I added microbes to it, weeks 7, 8, and 9 are the container size+ flushes

I get runoff from only feeding 1 gallon of water/tea, so up until the week 7 flush they have never had more than 1 gallon dumped on them, and they have been staying wet enough that I only water once a week, which I attribute to the top dressing amendments worm castings help retention and soil alive has yucca

can do an 8 and 9 week strain the same way because you can retard the flushings by a day, so on an 8 week the final flush would be on day 53 then let go 3 more days

for a 10 week I would do another tea, microbes, and light mother earth at week 6

 

[mexweed]

after the first 5 gallons through them the fan leafs and other foliage are looking really drained, the runoff looked like a tea though, they're going to get hit again tonight if the runoff starts to clear up I may just do container sized and not double or triple up, calyxes swelling and some new not orange pistils coming still

 

[00bladerunner]

SpacedCBWY...... do you find your stuff burns as good and tastes as good with the flushing agent??
I haven't tried the flushing agents yet but started looking into them. I add a lot of water the last 2 weeks with lots of runoff. But your right, the heavy water flushing is a lot of work and eats up a lot of time. So I'd definitely be interested in trying these flushing agents... maybe do a little experiment next time.

 

[Rico _El_Guapo]

I’ve found different outcomes depending on what media I’m using. Back when I used a 3 part I’d flush for the last couple weeks, but noticed the plants were a little shocked using a clearing solution.

I guess it was trial and error at that point.

I found that I washed away all the microbes and the plants didn’t like that. I ended up using a little bit of the run off water mixed with enzymes, and the plants seemed not to stress as much.

Now that I premix my soil (because I’m lazy, and I find it easier to just ph the water) I supplement with humic and folvic up to the last couple weeks, but still add some enzymes and carbs to the flush.

 

[Unk_OG]

Promix & 5 gal pots here. I use H&G Drip Clean the whole way along, including flush. What I do is, end of week 6 or 8 depending, flush 5 gal through, check runoff ppm. 10 gallons will normally get me to 200-300, then water/terpinator from there on out.

 

[Creeperpark]

I don't flush anymore because of bud rot! I just run pure water the last 3 weeks in soil-less! When the buds start getting super thick, then I start reducing water intake down a 1/3 to a 1/2 in the end! Clean smoke with out all that fucking watering labor!

 

[Unk_OG]

?

?

I don't flush anymore because of bud rot! I just run pure water the last 3 weeks in soil-less! When the buds start getting super thick, then I start reducing water intake down a 1/3 to a 1/2 in the end! Clean smoke with out all that fucking watering labor!

How do you get bud rot from flushing?

 

[Switcher56]

Good question? Humidity too high?

 

[Douglas.Curtis]

How do you get bud rot from flushing?

Low calcium levels can easily contribute to this... Definitely can be caused by a lack of transpiration from elevated RH, as Switcher56 mentioned earlier. Ty. Cannabis needs to either be cooling, hydrating or a balanced combination of both.

If your humidity is so high the plant has no need to stay hydrated, and your temps are low enough it requires little to no evaporation for cooling, the plant is not pulling water through itself very well at all. Bad things happen.

 

[Creeperpark]

High humility

High humility

Yes the RH is 67 right now everywhere, indoors and out. Last few nights the RH was in the 90s. Yesterday the temp was 80 F, 26 C and its the middle of Winter here! When a cold front shows up, the RH drops to the 30s & 40s
Those indica buds get very dense and stinky! Its the about the only way I can pull it off with out too much effort. I'm talking about soil-less peat mix in 5 gallon pot. I tried it both ways high TDS and low TDS! Using low ppms in Veg. I get bigger plants than High ppms with flushes. Since my yields increased using less ppms I'm staying with less. I dropped the ppms the taste is much better and the ash burns white.

I can say I've tried both ways with honesty, but can you?

 

[romanolescro]

hey bro let me bring my 2 cent

i spent some time before being satisfied with my buds

always looking for that clear white ash .. linked to flushing
with organic nute it will be less flagrant but with hydro if you give too much nute and dont flush .... black hard ash ... even shinny sometimes lol

with organic you wont really notice if it isnt well flushed. the only way to know is to roll a spliff and taste ... if you get headache after a big one there is salt left in the bud ...

let me tell you how to flush in soil

first you must not give too much nutrients during bloom ... if nute company tell you 4ml/liter, only give 2 and see
end of bloom when you notice bud are maturing cut mostly the N too

and the key is not to switch quickly from water+full strenght nute to just water

you must decrease the feed .. exemple

week 6 : 2ml of bloom 1ml of grow
week 7 : 1ml of bloom 0.5 of grow
week 8: 0.5 ml bloom 0 of grow
week 9/10: pure water

if you do this your bud will taste great

and no you wont loose on the scale, if you flush like i say you will notice your bud will explode at the end ... with nutrient till the end not realy ...

in hydro its pretty the same but you can do it without flush because you can controle the drain of your watering ... and always give the right amount

ex: 1.2 ms in and 1.1/1.2 ms on the runoff, you're in the sweet spot, and doing this way yes you can get away without flush and your product will still be good ...


your plants must not finish dark green !! that N will kill your taste !! fan leaves must fade but you must flush the P, k etc too ... so plain water is important at the end

peace my friends
hope im understandable, my english is far from good

 

[Noonin NorCal]

I water to runoff each watering...
I feed, next watering is tea and third watering is purified water to flush.
I cut off nutes and tea the last 3 weeks. I throw some molasses and brix in the mix too

 

[Creeperpark]

Thank you romanolescro, that is some very helpful information and a good read.

 

[de145]

I used to flush when I started because I kept reading that everyone did it but then I realized I could just stop feeding them earlier and save the hassle.

Maybe flushing is more applicable to commercial high yield strains and commercial growing where you're trying to pump out the very last gram?

With sativa leaning strains and for personal use I've come around to feeding a hell of a lot less than recommended and stop feeding far earlier than recommended and just observe the plant and what it needs rather than trying to fit a graph or schedule.

It also seems to cut down on pests when the leaves are not dark green and overfat with nitrogen.