Building a “Fallponic” RDWC system

So, I’ve watched the videos on YouTube from Gary at PA Hydroponics, on how he builds his systems.
I am basically going to replicate it, except I’m going to be using 27 gal black totes with black lids for grow sites and for the reservoir.
In theory I want 5 plants in my 4x8 tent.
But in my little bit of experience, I can fill it with 3 large plants. So I may just stick with 3 plants.
It will be fed with an 1110gph active aqua pump, through 3/4” pvc, dumping into the grow containers via waterfalls.
A 50w air pump will supply air to a 2x4” airstone in each container as well. Including the res.
I have 3” bulkheads and 3” pvc for the returns.
I have a 1/2hp chiller, which will be circulating the water from the reservoir with an 800gph pump.
I’ll be using Peters professional 5-11-26 nutrients, following the jacks 321 schedule from the time they have a couple nodes, until harvest.
With the addition of mkp at the start of flower.
And potassium silicate after training.
I plan on using hydroguard even though I’ll be using the chiller.
I’ll post pictures of the build once I get around to actually putting it all together. Hopefully some of you guys will have some tips for me. And maybe someone else might actually learn something Lol


Sounds like a great start.

If you ever need help just tag me in and I’ll be happy to lend a hand.


@Hotrod … I watched the same vids from Gary at PA Hydro and decided to switch from coco coir to his system. I have been gathering all the parts needed and I’ve been setting it up in my office. The blue tape on the floor, is the floor space of my 3x5x7’ tent in my garage. The milk crate shows the space for my portable AC unit that controls the temps. External Danner 700 gph pump behind the res outside of the tent. I also use a Active Aqua chiller too. It’s bassicThe new system goes into my tent after the current coco coir grow.

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Well I guess I forgot all about making this thread.
I had a pretty successful first run in it. The system is pretty much perfect, except for being a little bit hard to get the last couple inches of water out of the totes when changing water. Especially when the plants are bigger. But I just lift up a corner of each lid and vacuum it out, for now. Still need to come up with a better way. But I’ll post some pictures just in case someone can learn something or teach me something

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@Hotrod … Yeah, that last 2 inches of water is due to the 3" pvc. One reason why chose to go with the 2" pvc instead. And, since I’m only doing 2, 8 gallon buckets, the 2" is fine. I’ve been growing in coco coir for some time now, and thot I’d step up to a full hydroponic grow system. It’s been fun gathering all the parts, and putting it together. Just need to work my 15 gallon reservoir into the system that I use now for my auto water/feed with the coco setup. Can use it for a store and refill of nutrients for the small 8 gallon in the RDWC bucket and chiller that feeds the girls. Love your system. Looks great! I like how much cleaner the tent stays too with no soil or coco on the floor. What were your temps before and after the insulation around the pvc??


@RockClarke That insulation probably doesn’t help much, since I still haven’t insulated the totes or return line. Which I plan to do after this run. But I use a 1/2hp chiller and my water stays at a constant 68 degrees F

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@Hotrod thanks for the info. I should be good with 2 plants and my 1/10th HP chiller and 15 gallon res as a backup.


Hey brother you got a journal going right now?

I have a 4 13gal system, using a big bin for the resv only.

3” pvc seems very large. There’s gotta be a better way to prevent roots from clogging drains.

Gary sells a bottom drain kit - you just put the bins on bricks or etc, and the drain bulkheads feed to the bottom of the bins. Need to do this next time.

Anyone want 3” pvc unions or a 3” pvc true union ball valve?

@Jungle Yeah, 3" is over kill for anything less than 4 buckets. I grow for me, only. So, spending a lot of TLC on 1 or 2 plants, is more fun, rewarding, and less of a hassle than doing 8, as I have in the past. I will be using 2" PVC for mine. It’s a finished system, and I’m waiting for this ILGM Banana Kush to finish up in 2weeks. Then, flip from coco coir to the RDWC system. I have an RV fresh water pump that would be used for pumping fresh water to the kitchen & bathroom of the RV. Runs on 12 volts DC and I have a 3/8" hose that I can set at the bottom of a bucket, and turn it on. Thought about putting a bulkhead in the bottom front of the supply res, then hooking the hose to that too. That will drain the whole system except for maybe the last inch of water.
Hey @HappyHydroGrower … who are you asking that question??

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I am asking if you have one? :+1:t2::v::sunglasses:

@HappyHydroGrower No sir, I do not.

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Please explain. If 3" is needed to keep roots from clogging things up, why does the number of plants matter? The roots from several plants shouldn’t come anywhere near each other… ?

What I’ve done is have one 3" bulkhead on each 13g bucket, the return doesn’t flow through the buckets (each bucket’s return flow goes to a center 3" pipe (via two-way or three-way wyes). In Gary’s system, he puts two bulkheads on each bucket, and a third bulkhead on one of them… for a total of 2(N-2) + 5 bulkheads (where I would use N bulkheads only) … each are nearly $20, that’s a significant savings.

If 2" is sufficient for two buckets, it’d be cheaper to run 2" drains from each pair of buckets to the resv. 2" pipe, fittings, valves, and bulkheads are all much cheaper in 2" vs. 3".

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@Jungle It’s not so much that the PVC gets clogged. It’s the pump, internal or external that will get clogged. When small pieces of older roots break off, you just need to contain them. You can put small screens, cheesecloth, nylons or almost anything over your PVC to keep the roots inside the bucket. Just have to keep them from traveling through the system.

So some kind of filter in front of the return pump is necessary, ok. But why bother with 3" pipe? The buckets are being filled via a much smaller pipe (and a pump that probably can’t use the full capacity of the pipe anyway), so 3" is overkill.

Here’s what Gary does:

Here’s what I did:


(supply lines not shown)

I use 1-1/2” pvc in and 3/4” black tubing out for return. But, I will admit, my systems a little different than what y’all are running.


Since I’m in the grow room every so often, I just fold the roots back over themselves.

Runs problem free as long as I pay her some attention once in a while. Have only had roots get in the system once on my first grow. I learned to keep an eye on things.

Ah, yep. That is different. You’re pumping water into the reservoir, instead of pumping water from the reservoir to the grow containers.

and wouldn’t you know, a 3" netpot fits tolerably well into 3" PVC, so I have some kind of filter between the return and the reservoir.

@Jungle … when the system is setup properly, that smaller line/pipe that feeds the buckets, will fill those buckets to a level that is higher than the res. Gary says that, in his video. The 3" PVC return line is capable of getting that nute solution back to the res and chiller much quicker. I’m using two 8 gallon buckets that will be fed with a 700 gph Danner external pump. Return line is 2" PVC. I’m going to put some small filter over the return line before it returns to the res.

Also, here is where I buy my bulkheads. These are the really good one’s with a big rubber gasket. 2" is $13.50 and 3" is $14.50
Be sure to buy the wrench too! It’s only 6 bucks.
Under Current Spin Tight Bulkheads | HTG Supply Hydroponics & Grow Lights Store

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Yes, of course the water level at the plants will be slightly higher than the reservoir. But that’s the case even if you have 8" return :).

The difference between them would be related to the supply rate (e.g., 700gph), the drain rate of a 3" pipe is as high as 130gpm (130*60 = 7800gph)… as long as the drain rate is somewhat higher than the fill rate, the water level differences are going to be minor.

Do you find it differently?

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@Jungle It will only return as much as you put in. The higher rated pump ie 700, 1000, 1450 gph, will add more water to the grow buckets creating more head pressure, or down force pressure on the water level in the grow buckets. This is what pushes the water back to the res,