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Flushing Duration RDWC

Aroxol

Well-Known Member
Hey Guys and Gals,

Looking for some input on RDWC flush times. I understand some people don’t flush - awesome - but this post is for the people who do so they can offer input. I don’t want this post to get bogged down or turned into a debate about flushing, simply curious how long RDWC generally takes as I’ve read varying opinions.

So far I’ve run 6 hours of Flawless Finish, drained, and am now running pure RO water. Normally I’d go by yellowing leaves, but I’ve got to head out of town soon and need to make decision on running RO for 1 day vs. 3-4 days.

Wondering how many days typically suffice? Thank you!
 

Aroxol

Well-Known Member
Think you’re left to my guidance and limited (although sound) wisdom here, Sativuhhh.

Understanding this is my first run at DWC/ RDWC - I can tell you with confidence 6 hours of Flawless Finish (or any other flushing agent) + 36 hours of pure RO water isn’t long enough. Take it til you start to see yellowing leaves. My guess is that’ll be 4-6 days, then chop WHOLE plant and hang.
 

LiberalThinker

Well-Known Member
This what I'll be following with my first DWC. This is a General hydroponics-based scheme, which gives two weeks flushing.

1741607
 

Aroxol

Well-Known Member
Since this is your first DWC and I’m wrapping mine up, here some Informational Only takeaways that I had. May or may not prove valuable or useful to you, but sharing nonetheless. Lmk how the flush works out, I think you’re plant will do more than fine for 2 weeks. Wife said mine hasn’t even yellowed after 4 days. I’ll see tomorrow when I get home, but it’s coming down either way.

What I found:
-Figure out a way to ensure your shit doesn’t flood or lay things out in a way that’s eas(ier) to clean 5-10 gallons of water and nutes our of a tent. Seriously, think through this ahead of time.
-You don’t have to run DWC specific (mineral) nutes or have a super sterile/ pristine res. If you want ultra white roots, you do, but if you want more organic style weed you don’t.
-I saw best results with 64F water temp.
-If running with RO water, use EC as single source of the truth for feeding; I don’t think I’ll go above 1.6-1.8 max EC in future DWC grows. Also add calmag, but pretty sure you already know that.
-Use same water source throughout grow.
-Feed on the lighter side of what you think is needed, DWC is definitely different than coco.
-Change water at least every 20-30 days.
-Reduce feed under .6 in final week before flush.
-Start flush at least 6-7 days out from harvest moving forward.
-If you have a pH or deficiency issue mid run; drain res, flush out with flawless finish or a chelate based flush formula for a few hours, drain, then run RO water and add reduced feed back in. I’ll admit, I’m a hater of overpriced nutrients in a lot of cases, but with DWC a pure RO flush did not work even close to as well as when I used flawless finish to remove all buildup (you’ll know by EC measurements - this goes back to using EC as your single source of truth).

Good luck, send me a note when you start your journal and I’ll tag along.
 

LiberalThinker

Well-Known Member
Thanks for sharing your experience so far. I shall definitely be doing dry runs of processes and routines I'll need to go through and find the correct position for access. I'll be hanging light-proof material from the ceiling to the floor in the corner of a room where there's a vent to fix a fan over it, so I'll have more access points than from a tent. It' certainly seems more involved than soil growing. I'll let you know when I start a journal. I anticipate in a month or two.
 

Aroxol

Well-Known Member
It’s just different, a lot of upfront work. Key difference is you can really automate a lot and basically set the grow to cruise control once you’re dialed in. I’ll probably run a mix of coco and RDWC in the future, but need to redesign my setup to 100% eliminate any chance of floods.
 

Indiva710

Well-Known Member
Not sure I'f you have built your setup yet but if you haven't you should check out mine it is a very legit rdwc setup I didn't go cheap on anything very clean..I have access to every inch of the entire system to fully scrub and clean between grows which is a must have at least every other grow should be broken down scrubbed and cleaned...
I never have had much luck running Bennie's in dwc or rdwc..I also find it quite pointless as well as they are just not needed as hydro nutes are chelated so they are available right away unlike Coco/soil plus they live longer in Coco and soil..
68°f is the best water temp to run as it has thee most dissolved oxygen available at that temp than any other...
For Dwc I do h2o changes 7-14days also depends on the plant if the pH is all over the place and not stable or if the plant is having issues etc...Now in a rdwc setup which I have a top off res which has next week's nutes in it so as the plants drink it slowly goes into the system and has fresh batch of nutes...I will do a system change if pH is very off and isn't stable like it should be however it does fluctuate throughout the day and it raising is actually a good thing and shows the plant is feeding actually it's just something that happens so that's pretty normal...
Now my last grow in rdwc I did a water change 8wks into veg and I didn't do a res change until the last few days before I chopped for flushing I also only flushed for 3-4days last grow was at 480 ppm then went half that 240 the last 2 days and went to 0ppm for 24hr and. Then after I harvest since the system is at 0ppm I'll run a mix of pool shock,bleach, h2o2 will run it for 24hr w the pumps on like normal scrub every inch of the system...
If your using airstones which in dwc u would be and if u get clogged stones there's a few things u can do to fix them.. some will boil them sometimes I've heard w a few drops of bleach too to boil them or w vinegar..What I usually will do is vinegar diluted with water also depends on how bad the stone is if it's terrible I'd do even pure vinegar like in cup so u don't have to use a drum of it lol.... I will run my airpump and hook the stones up and let them bubble however I will let them soak prior to running it but it does wonders....
Ya also running a chiller with several dwc buckets is impossible as u need a pump to run a chiller and that would mean it's a rdwc system.. However for like a single dwc plant system you can hook up another bucket as for a larger reservoir and you could have a fan as a chiller you put a hole in the lid for the fan to blow into the res and cut a hole opposite side for a exhaust and there's one cheap and very cheap to run chiller..And you can get a ink bird temp controller hook it up to and it can be controlled by a certain temp and call it a day .....
 

Indiva710

Well-Known Member
Have you seen the octopots before or autopots might be something you would be interested in... Also in your loft if your worried about water leaking with a rdwc setup your best bet would be one of the options I mentioned above or even better yet would be aeroponics specifically high pressure aeroponics it uses 10% water of what a rdwc setup does period..It uses a high pressure pump and aero sprayers for ur system which it's something I'm highly considering over my perpetual rdwc setup I currently have actually....
As it would be nice to use like 10gal a week in full bloom vs 55gal big difference In nutes and water....
I also only run dry powdered nutrients now no more liquid trash def not paying for 98% water if not more in liquid bottles period... Plus its like 90% cheaper too...Jacks professional is a great company for nutes which it is a 3part..Which is the way to grow cannabis ESP with all the different strains and phenos wanting diff things and when you can give the plant exactly what it needs no problem...
Tbh I refuse to use calmag as well..Now don't get me wrong I use calcium and mag but only when the plant needs one or the other it is quite rare for the plant to be deficient in both cal and mag at the same time esp when the plants are getting their base nutes on top of it...So jacks hydro is the part a ..5-12-26 and then calcium nitrate aka part b 15-0-0 and mgso4 aka epsom salt aka magnesium sulfate ...The ratio for each is 3-2-1 so say 3.6grams per gal of part a 2.4g of calnit part b and 1.2g mgso4...
And of course they can be tweaked when needed and a pc program called hydro buddy for that stuff is perfect for it you can dial in your notes very precise...
And silica is like a must have for hydro esp if you train your plants and use a scrog net if not the branches will snap clean off and will only harm your plant and yield....I even use dry pH powders too now just my days of buying liquids are long gone lol
Check out my journal if u want to see more of my grows and if u have any questions I'm happy to help
IMG_20190715_101158.jpg
IMG_20190813_000053.jpg
 

mojuan

Well-Known Member
Since this is your first DWC and I’m wrapping mine up, here some Informational Only takeaways that I had. May or may not prove valuable or useful to you, but sharing nonetheless. Lmk how the flush works out, I think you’re plant will do more than fine for 2 weeks. Wife said mine hasn’t even yellowed after 4 days. I’ll see tomorrow when I get home, but it’s coming down either way.

What I found:
-Figure out a way to ensure your shit doesn’t flood or lay things out in a way that’s eas(ier) to clean 5-10 gallons of water and nutes our of a tent. Seriously, think through this ahead of time.
-You don’t have to run DWC specific (mineral) nutes or have a super sterile/ pristine res. If you want ultra white roots, you do, but if you want more organic style weed you don’t.
-I saw best results with 64F water temp.
-If running with RO water, use EC as single source of the truth for feeding; I don’t think I’ll go above 1.6-1.8 max EC in future DWC grows. Also add calmag, but pretty sure you already know that.
-Use same water source throughout grow.
-Feed on the lighter side of what you think is needed, DWC is definitely different than coco.
-Change water at least every 20-30 days.
-Reduce feed under .6 in final week before flush.
-Start flush at least 6-7 days out from harvest moving forward.
-If you have a pH or deficiency issue mid run; drain res, flush out with flawless finish or a chelate based flush formula for a few hours, drain, then run RO water and add reduced feed back in. I’ll admit, I’m a hater of overpriced nutrients in a lot of cases, but with DWC a pure RO flush did not work even close to as well as when I used flawless finish to remove all buildup (you’ll know by EC measurements - this goes back to using EC as your single source of truth).

Good luck, send me a note when you start your journal and I’ll tag along.
taking note, going on my 1st run after thanks giving after a complete overhaul of my grow room
 

Stltoed

Well-Known Member
Have you seen the octopots before or autopots might be something you would be interested in... Also in your loft if your worried about water leaking with a rdwc setup your best bet would be one of the options I mentioned above or even better yet would be aeroponics specifically high pressure aeroponics it uses 10% water of what a rdwc setup does period..It uses a high pressure pump and aero sprayers for ur system which it's something I'm highly considering over my perpetual rdwc setup I currently have actually....
As it would be nice to use like 10gal a week in full bloom vs 55gal big difference In nutes and water....
I also only run dry powdered nutrients now no more liquid trash def not paying for 98% water if not more in liquid bottles period... Plus its like 90% cheaper too...Jacks professional is a great company for nutes which it is a 3part..Which is the way to grow cannabis ESP with all the different strains and phenos wanting diff things and when you can give the plant exactly what it needs no problem...
Tbh I refuse to use calmag as well..Now don't get me wrong I use calcium and mag but only when the plant needs one or the other it is quite rare for the plant to be deficient in both cal and mag at the same time esp when the plants are getting their base nutes on top of it...So jacks hydro is the part a ..5-12-26 and then calcium nitrate aka part b 15-0-0 and mgso4 aka epsom salt aka magnesium sulfate ...The ratio for each is 3-2-1 so say 3.6grams per gal of part a 2.4g of calnit part b and 1.2g mgso4...
And of course they can be tweaked when needed and a pc program called hydro buddy for that stuff is perfect for it you can dial in your notes very precise...
And silica is like a must have for hydro esp if you train your plants and use a scrog net if not the branches will snap clean off and will only harm your plant and yield....I even use dry pH powders too now just my days of buying liquids are long gone lol
Check out my journal if u want to see more of my grows and if u have any questions I'm happy to help
IMG_20190715_101158.jpg
IMG_20190813_000053.jpg
Looks good
 
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