Considering Switch to Coco Coir - What about RDWC?


I run a top feed system and had to learn the amount of water that I could allow and it still be ok.

I took this

To this


We have all had similar experiences. All because of rockwool. Abandoning it for rapid rooters or root riot’s


My thinking now is to go ahead and build a four bucket system. Would prefer six but unless I can wheel them around like I do my current FFOF grow with individual SCROG frames, I must limit to four so that I can get around them for inspection and discussion LOL.

It would be great if there were some plans available rather than reinventing the wheel.

The biggest concern is sizing the air pump and the water pump. Biggest concern is water pump…don’t need over flow or plugs happening. Mrs Merlin would freak out if I flooded the basement ROFLMAO.

If you guys have a recommendation for pump sizes for a four 5 gallon bucket system, that would get me started.


So I alluded to all the “tinker toy” shit you have to deal with in RDWC but if you are handy it’s not going to be insurmountable. I would definitely favor RDWC over straight bucket-hydro for two reasons: better temp control (rez being outside grow space, ideally) and longer run times. My 3 plants are using between 3 and 4 gallons per day and I’m just starting week 3 of flower. If you balance the nutrient load, the rez can carry your feeding for as long as there’s water in the tank.

I know you go out of town on occasion so methinks this would be a better fit than either coco or DWC. Just my thinking on the subject.

If you go the tote route I would get something between 12 and 15 gallon capacity: they will be less than half full and 5 or 6 gallons seems to work pretty well.


You should probably go bigger if you go RWDC. I’ve had grows absolutely fill the 5 gal bucket. You don’t want roots getting sucked into the plumbing of the recirculation loop.


Check out this thread @merlin44

Only 26 post so its not too long

From Soiless to Hydro


Use at least a 90mil bucket and learn to use uniseals and you can build some great systems


Late to the party,but I love coco. It’s super easy to use, can flush things easily, plants show and correct issues faster and the growth rate is amazing. I’ve put soil clones into coco and have had great success.


Great to know, thanks man! I don’t know if I will get the RDWC built in time for this grow so may need to do just that.

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I just unpotted the clone, shook off as much soil as I could and put it in the coco. Also, pH issues are almost null since you control it all the time. Now buffers or bat poop or whatever to cause hot spots etc.


I haven’t done the coco route either although if I was planning to switch from RDWC it would be my other choice. I can say I wouldn’t use buckets for a RDWC system just because long veg cycles would easily out grow it. I’ve got a clone in a 6.5 gallon bucket right now. She’s about 14 weeks in veg (don’t ask lol) and she’s pretty much out of root space. But considering normal plant life it’s easy to see how you could run out of room. And the bigger the system the more stable the ph is and the longer you can leave it unattended. My new setup is going to be 5x 27 gallon totes that will hold 2 plants each and a 17 gallon tote for reservoir. I’m guessing around 105 gallons total. But that’s where the bigger systems get easier. It takes way more nutrients to get it started but my last run I only changed the water twice. Once before going into flower and once for flush days. The rest of the time you just add more nutrients to increase the PPMs. So if easier growing less maintenance is what you want RDWC is the way to go. But initial setup is a bit more expensive and it requires building the system. But that’s the only hard part.


@merlin44 I know little of coco and even less of hydro. I have researched coco grows and methods and probably will go to that at some point just to see what it is about. I would think that with your approach to growing hydro would best suit you, it just seems to be a better way to get consistency to me.


:+1: very true


Spot on with that statement lol


What? I have been trying to grow with dwc for a couple months now with no success (finish product) everything dies eventually. They start off really strong then dark spots and leaves curling in. And I check my ppms and pH daily! What nutrients are u using?

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When was the last time you calibrated your pH pen?

You can always test if your meter is right by comparing it against the readings with this kit too which is very cheap

General Hydroponics 722145, 1-Ounce PH Test Kit, 1 Ounce

Other than that make sure your roots are healthy looking


@JPK. Welcome to our community. You will find a lot of helpful ppl here.

GH Flora trio. Lucas (8mlM/16mlB/gal)

If you are getting die off I would really question your nutes. Do they contain organics and sugars. These would definitely lead to blooms of anaerobic bacteria in the DWC and this would lead to a snotty mess and lack of O2 at the roots.


You got a lot of answers, but I’ll add to what I saw missing for getting from seed to seedling in hydro.
What MacG does is he allows the sprout to grow a really long tail on the moist paper towel method until the first leaves come out.
Then he drops the fragile seedling into a neoprene foam collar with the leaves just above that surface his home made cloner. Fills to the proper water level, and allows the air stone to “splash” the roots with water. You can purchase a cloner as well, but this would just remove the issues with removing soil from the roots. Which works also.

I’m only relaying what I’ve read, I have no experience and have never done any of this, but I do want to try this very soon. Soil isn’t expensive, but it’s an added cost. @merlin44


I always felt like I was just guesstimating with the liquid pH test kit I still have it tho. I’ll give that a try when I get back. See what the difference is. Hopefully it’s that! Lol thanks


That’s where I’m confused I use the 3 part grow nutrients. And I go by the chart that they had on the back of the bottles but is just a general kind of chart it’s not very specific. Because as a new grower I can’t just look at my plants and know when they’re in what specific stage time table time chart with the weeks I think would have been a little bit better for that. Do you go exactly by that chart? and what weeks are the cuttings in seedling stage. What weeks are general-purpose mild vegetative? That’s what I feel like throws me off a lot

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