Submersible pump for RDWC.

How would I go about putting together a RDWC system with a submersible pump. Every system I see is an inline re-circulation pump.

Maybe its just me being dumb as hell at the moment or stone outta my mind but. I cant for the life of me figure out how I will use a submersible pump to run a RDWC.

A pump kinda like this is what I am looking at.



396 GPH and only around 25 bucks.

I have been looking at the inlines and to be honest dont really wanna spend 50-75 for a small pump. Building this room of mine on a budget. (4x8' room if anyone has seen my other posts)

Ideas? or know how?

Pipe pails out the bottom into the res and pipe discharge to top of each pail i would think lol, not sure really but lots of plans Im sure. I built a flood and drain using totes, to take up less room, so i thought.

Get an ecoplus 185 that can do both inline and regular for $15.

Oh ya i use a eco 165 pump, works great! It would be nice if you could creat a waterfall effect at top of each pail, then perhaps no airstone would be required.

twistedwords said:

Get an ecoplus 185 that can do both inline and regular for $15.

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I will have to look into those. Thanks man.

waterdawg said:

Oh ya i use a eco 165 pump, works great! It would be nice if you could create a waterfall effect at top of each pail, then perhaps no airstone would be required.

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This was my plan. I didn't want to use the air stones. Been finding a load of people not using them and only using the waterfall effect. I love the idea. Want to give her a try. What could it hurt if all else fails its easy to add a few air stones and a pump to any kind of set up.

I was thinking I needed a little bigger pump then the 165 or 185. I will be running 8 total buckets. But I think I figured it out.

I seen the Eco 633 that is 594 GPH.

I talked to a guy I know about these pumps and I didn't realize that the front cage is removable and can be built to do a non submersible inline installation.

I found the Eco 633 for $38. And that fits in my proce range and should have enough if not more then enough power to run what I need it to do.

Thanks for the reply guys.


One more question and see what you guys think. Never tried the waterfall effect but wanted to. Do you think having one large water fall be circluated threw 8 5 gallon buckets would be enough or do you guys think I will need the water falls in all buckets.

Redesigning my setup as I added 4 buckets up from 4. So a total of 8. Bigger room then I though figured I wanted to use some of the space.

The water fall to all buckets wont be a problem. Just curious to see what you guys think.

I use 2 submerged pumps on a 4 site rdwc.

1st pump feeds the plants through the lids on each bucket, the other is used for churning the res and has an airline attached to it. I don't use any air stones and have never seen any signs of overwatering.

Both pumps are cheap powerheads from petco. This setup did require insulating the buckets and use of a chiller, though. (I use an iceprobe)

did you figure it out ? you need a res bucket with all your buckets plumbed to it . Dunk the pump in the res bucket and use the outlet nipple to run your top feeds.

Thank guys that is what I was thinking. I am going to finish drawing it up and then get on way to getting prices. and then I guess build.

It was going to be 9 buckets total. well 8 buckets and a 10 gallon tote. so there is extra room if needed.

Thanks again. I will post what I get drawn up. May need a tweak or two.

this thread helps explain a lot https://www.rollitup.org/dwc-bubbleponics/497270-how-rdwc-ucdwc-diy-advanced.html

Thanks for the replies guys. They are greatly appreciated.

This is what I have drawn up. I still may need airstones unless I get another pump to flow to each bucket for a sort of water fall top top transfer to bucket. I was thinking of using 1/2 ID or 3/4" ID hose for this with a smaller pump then used to circulate.

Let me know what you think. I really dont want the hassle of air stones. Besides I have read that airstones really dont add DO to the water its the action of the bubles popping at the surface of the water that adds the O2 lind of like a fish tank filter creating the small water fall in smaller tanks.

What do you guys think?

Check out current cultures website for a few ideas on how they set up their systems, they are MASSIVELY overpriced but you can build one with a little DIY knowhow for around $300 as compared to the $1,000+ they charge for their systems. Either way, regarding your pump question, it's best to get a high quality pump that isn't going to shit the bed on you, I use a mag-drive 250 GPH pump for my 4 site 1 res RDWC setup. All the buckets are connected via 2" PVC piping and made leak-proof with uniseals. Your buckets will be placed in a way where the pipes that connect them are in line with eachother to allow for optimal flow of nutrients. At the far end of your two rows of buckets (go with two rows as it's easier to design and setup) there will be a pipe connecting one row to the other thus forming a full circle of pipes starting at the res, going from one bucket to the next and finally finishing back at the res. As far as pump placement goes, at the far end I previously discussed, you will need a threaded tee, 2" PVC on the connector sides and a threaded outlet in the middle (the tee part). If you go to lowes you will be able to find the matching size threaded hose adaptor. This adaptor will be screwed into the tee and then connected to the pump with vinyl tubing (whichever size fits the specification for the pump, generally they are 0.5 to 0.375 inches, get a threaded to barbed hose adaptor) which is NOT submersed in water but rather run in an inline fashion. The outlet to the pump (located on the the top) should then be connected back the res with additional hose / vinyl tubing. What this accomplishes is a circulation of nutrients throughout your whole system. The pump pulls water through each of the buckets as the are all connected to eachother with the 2" PVC pipes, and as this water gets pulled through the system, the pump then deposits the nutrient solution back into the res and the circulation process continues. Hope this helps!

IMO. Anything that is electric will conduct heat. You don't want heat in your water. Rdwc needs cold water to perform correctly (better oxygen. I would spend the money on an inline pump. Once again, my opinion.

I checkout out there site. Massively over priced for sure. $1,800 for almost the same system I am gonna build. Different parts of course but that makes me almost want to expand my business and build a few system to sell online. I have an extensive background in commercial construction and worked as a pipe fitter as well as a engineer on a frac crew. I am sure I would be able to build some pretty fair systems for people. You just gave me a great idea here. I know its a little off topic but thanks man.

and yes your post did help a bunch. The re-circulation pump I was thinking of using vinyl hose instead of a pvc pipe as i do not really like pvc. hot to cold it gets brittle over time and is easy to break.

All the connections were going to be made with using uni-seals and 2" pvc pipe. The pump I was going to use was the Eco 633 which pumps at level 594 GPH. Which is plenty and using a vinyl hose should be able to build enough pressure to force a mix at the res. So I am thinking anyways. Now keep in mind that I was going to be building this system without an air pump or air stones. The amount of DO will have to be from a waterfall or a force burst of water to each bucket or a massive burst to the res. Which has to be circulated enough to place the DO in each bucket as needed. Which I am thinking I will need a separate pump to do this with as I do not think I can circulate fast enough to keep DO up at each site or root zone.

DO can also be created in a bucket via spray nozzles. A smaller pump with a smaller connection bigger then an airline of course could be used to spray the interior of the buckets to create the DO at water level. There for smaller pump less wattage, less movement of water threw tops of the buckets and a massive flow threw the bottom of the buckets should be enough to create the DO needed to supply the plants with the DO required for each plat to bloom successfully. I have seen one other grow that used sprayers for creating DO instead of a waterfall and they had a successful grow doing this. I do not mean Aeroponics either. They used the sprayers not to spray there roots but to spray the interior to create the DO at the surface. And they used no air stones or air pumps in there system Just another idea if needed that is all.

I was thinking of placeing the res outside the room to keep the temps lower. I figured winter time 50 degree give or take will be enough to help keep the water I would guess around 60-70 depending on a few other things. I will have to see when I get everything built setup and running to know what he temps will acualy be during operation. And I may even run the system without planst for a few days so I can adjust to the conditions and try to stabilize the set-up as best as possible before cracking some beans. As I am running Auto Fem NL and auto fem KC45. Saving the other beans I have to force hermie in the fems to get the seeds for the future runs. Gotta make me some colloidal silver.

Oh and to let you know all know. I have priced all parts needed to build the system. With 2 water pumps, net pots, buckets, PVC Pipe & Elbows, seals, coco coir or hydroton, vinyl hose, ran a little over $200. $205.63 Actually. Fair price for a cheat 8 site system in my opinion compared to the site suggested for ideas which was around $1,800.00. OUCH I need to .

buckeye9 said:

IMO. Anything that is electric will conduct heat. You don't want heat in your water. Rdwc needs cold water to perform correctly (better oxygen. I would spend the money on an inline pump. Once again, my opinion.

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I like your option and it matters. To me anyways. That is what I want to use is an inline pump. I do not want the pumps in the res what so ever. Simple because of what you said. Heat. Cooler the better. The cooler the water the more DO it can hold. Which I would assume is essential in a setup with no air pumps or air stones. Which is what I plan on building.

Thank you all for contributing it is appreciated.




So you all know I have started a journal of the entire project. From start (building the room ,setup and cracking beans). I will be updating it as things progress. I will be posting it so al can view here soon.

Thanks again guys.

Everyone repeats how much better cooler water holds DO but nobody ever seems to look at the curves in the range that apply to DWC. It's a very small drop in total saturation for every degree warmer.

at 68F, it'll hold 9.2 ml/L
at 77F, it'll hold 8.6 ml/L

Don't let DO stress you.

Higher temps will allow for slime and what not, and is the real reason to keep your temps low.

Here is what you do OP, since someone earlier on this thread already told you what to do. You get two pumps. One is used to circulate the 1/4 in drip lines to the top of buckets and the 2nd one is used to recirculate the water in the controller only with an inline air attachment(it creates a venturi) and this will oxygenate your water and no need for air pumps. Done and best solution possible. Also keep your controller and reservoir outside of your growing area or tent(preferably in a cold room) as this will kepp your controller cool and water cool naturally.

Here is how the venturi works and the best way you can do it. air pumps can't do this.

http://www.youtube.com/watch?v=_lN_S2GOAfM

This is awesome. That's exactly what I need. Oh and they sell power heads at walmart for $21. Cheap and I think will do the trick.

Thanks man.

EDIT*** And I went back threw and read the other posts. I see that this was brought up before. Sorry pretty sure I over looked that. Thanks to both of you.

Also there are tutorials and demos of there power head type oxygenated on YouTube. Don't remember the names just remember watching them last night.


Thanks again guys

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You mean like this? Now, it is an outboard rez, which I prefer as it makes replenishing/changing nutes much easier. First 2 pics are various iterations. I now simply let the 1/2" elbow shoot the nutes onto the rocks

Pic3 uses the 160 gph pump in a 2.5g pail. The system is too small for larger plants

I like that setup man look nice.

BUt what are the pros and cons of something like that?

The way I am thinkin that the powerhead in the main res would be good for mixing nutes and also aeration. and prolly would be cheaper to use aswell. As the powerheads only run around 20 bucks.