Thoughts On Recirculation Methods

Hi, folks,

Here are a couple of evolving illustrations of a Waterfall/Top-Feed Recirculating-DWC system I'm designing:

Schematic:


Sketchup model:


I'm personally drawn to the idea of a pressurized feed line for a few reasons:

a) I can take a top feed to a drip ring which will allow me to plant seedlings at the optimal height inside the netpot and feed them around their perimiter, which means I get nice, wide roots, and I don't have to overfill my container.(compared to UC: no built-in top-feed)

b) I can run the whole thing using small, inexpensive, immersible head pumps inside the controller so I only have to plumb one side of the pump. (I'm not worried about res temps till summer, but I have an external pump, too, JIC)

c) Each container requires only one large, pressure-sealed opening (UC = more points of failure, more labour, higher parts cost).

d) Any site can be seamlessly isolated from the system with valves if necessary (UC: impractically difficult to isolate sites).

The Questions:
1) I've compared this method to Undercurrent, and though it seems popular these days, I'm unclear on the benefits of having the return line under pressure rather than the feed. As long as the low-pressure pipes have the passive capacity to keep up with the high-pressure-side flow does it really matter which way we're pumping?

2) Considering the upshots I get from Top-Feed/Waterfall, are there any reasons to keep investigating UC?


Any takers?



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MisterWhilom said:

Hi, folks,

Here are a couple of evolving illustrations of a Waterfall/Top-Feed Recirculating-DWC system I'm designing:

Schematic:

Sketchup model:

I'm personally drawn to the idea of a pressurized feed line for a few reasons:

a) I can take a top feed to a drip ring which will allow me to plant seedlings at the optimal height inside the netpot and feed them around their perimiter, which means I get nice, wide roots, and I don't have to overfill my container.(compared to UC: no built-in top-feed)

b) I can run the whole thing using small, inexpensive, immersible head pumps inside the controller so I only have to plumb one side of the pump. (I'm not worried about res temps till summer, but I have an external pump, too, JIC)

c) Each container requires only one large, pressure-sealed opening (UC = more points of failure, more labour, higher parts cost).

d) Any site can be seamlessly isolated from the system with valves if necessary (UC: impractically difficult to isolate sites).

The Questions:
1) I've compared this method to Undercurrent, and though it seems popular these days, I'm unclear on the benefits of having the return line under pressure rather than the feed. As long as the low-pressure pipes have the passive capacity to keep up with the high-pressure-side flow does it really matter which way we're pumping?

2) Considering the upshots I get from Top-Feed/Waterfall, are there any reasons to keep investigating UC?


Any takers?



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Click to expand...

Hey MW, I'll take a shot.

The design you have made is essentially a RDWC setup, however the recirculation would be minimal. With only a top feed line from the res to the buckets, essentially the piping between the buckets would only serve to maintain an even water level, ph, and ppm throughout the whole system. However you would need to add an air stone in each bucket and a big enough air pump to add enough oxygen to the solution. The theory behind UC is to recirculate the entire systems volume fast enough to maintain an even level of DO throughout the entire system, therefore reducing, or eliminating entirely, the need for air stones, pumps, etc.

A) You can add a pressurized top feed line to any system type you want...however the benefits of the top feed line as you have it would be null after the roots hit water.

B) Pumps honestly don't cost enough for that to be a sensible reason. If you add the cost of air stones, pumps, tubing, fittings, and extra power to run them, the cost of two pumps or a large pump is negligible.

C) If you use the correct materials and don't half-ass a DIY, leaks shouldn't be a concern regardless of entries and exits. Again the changes and materials cost is negligible.

D) Why would you ever need to isolate 1 site? Chances are, in a recirc system, if 1 site has a problem all the sites have that problem, and it is impossible to eliminate this unless you isolate all the sites from the beginning and at that point you are DWC, not RDWC. Plus you would have to kill the top feed if you did isolate one cause if you don't, it will flood.

Check out my design, the link is in my signature. If you have any questions, I'm here to help as much as I can.

Chadster152

i will help you and then maybe you can help me ...first question. idk basically what your saying about the pipes under pressure but basically what you want it a tub (resevoir) full of water, a water pump in there with tubing pumping water to the 4 areas, then from there you can run a feeed line for the top if you want although i think its not necessary, but its whatever u want. personally i would do what your doing but instead of DWC i would do aeroponics.. which basically means instead of being filled up with water the whole time, just tubing inside the bucket and use little sprayers to spray or mist the plants roots that way they gets lots more oxygen and all the water they still want. number 2. i would investigate and study and research all methods, it doesnt hurt and its good to get as much knowledge as you possibly can, i suggest aeroponics but its your choice in the end. now i want to ask you a question, how did you do up that cool schematic design and stuff? like the picture u used to show it is really cool, how did u do that, like what program did you use to ''draw'' up those diagrams. that type of stuff really intrests me and i like your little picture design, ESP your second pic the ''sketchup'' model or picture. lol, thanks later bro

chadster152 said:

Hey MW, I'll take a shot.
The design you have made is essentially a RDWC setup, however the recirculation would be minimal. With only a top feed line from the res to the buckets, essentially the piping between the buckets would only serve to maintain an even water level, ph, and ppm throughout the whole system. However you would need to add an air stone in each bucket and a big enough air pump to add enough oxygen to the solution. The theory behind UC is to recirculate the entire systems volume fast enough to maintain an even level of DO throughout the entire system, therefore reducing, or eliminating entirely, the need for air stones, pumps, etc.

Click to expand...

Hey, thanks for the reply.
It seems to me that, given a system volume of about 100 liters (like this one), a 2000-LPH pump will circulate the water in 20 times an hour, so I'm unclear on what you mean by "recirculation would be minimal". I intend to use airstones in all the containers.

chadster152 said:

A) You can add a pressurized top feed line to any system type you want...however the benefits of the top feed line as you have it would be null after the roots hit water.

B) Pumps honestly don't cost enough for that to be a sensible reason. If you add the cost of air stones, pumps, tubing, fittings, and extra power to run them, the cost of two pumps or a large pump is negligible.

C) If you use the correct materials and don't half-ass a DIY, leaks shouldn't be a concern regardless of entries and exits. Again the changes and materials cost is negligible.

D) Why would you ever need to isolate 1 site? Chances are, in a recirc system, if 1 site has a problem all the sites have that problem, and it is impossible to eliminate this unless you isolate all the sites from the beginning and at that point you are DWC, not RDWC. Plus you would have to kill the top feed if you did isolate one cause if you don't, it will flood.

Click to expand...

A) Correct.
B) True, this is a fringe benefit.
C) I don't live in America. Parts and materials are expensive and difficult to obtain where I'm at.
D) Seems like a handy option to me.

chadster152 said:

Check out my design, the link is in my signature. If you have any questions, I'm here to help as much as I can.

Click to expand...

Looks good!
Thanks for the reply!

aknight3 said:

i will help you and then maybe you can help me ...

Click to expand...

Cool.

aknight3 said:

personally i would do what your doing but instead of DWC i would do aeroponics...

Click to expand...

Aeroponics is not up for consideration at the moment.

aknight3 said:

now i want to ask you a question, how did you do up that cool schematic design and stuff? like the picture u used to show it is really cool, how did u do that, like what program did you use to ''draw'' up those diagrams. that type of stuff really intrests me and i like your little picture design, ESP your second pic the ''sketchup'' model or picture. lol, thanks later bro

Click to expand...

Thanks for the kind words.
The schematic was made using Google Apps Drawing. The 3D image was made using Sketchup.

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I'm wondering why you chose the location you did for the res? Are you having multiple lights at the side? It seems to me hanging a light from the center - above would provide a lot of light/heat for that res. Personally I would tuck the buckets a tad closer together and pull the res farther out.

outlander1 said:

I'm wondering why you chose the location you did for the res? Are you having multiple lights at the side? It seems to me hanging a light from the center - above would provide a lot of light/heat for that res. Personally I would tuck the buckets a tad closer together and pull the res farther out.

Click to expand...

Right now the control bucket's location is restricted to the confines of the tent in which the system is contained.
I could move it out if I raise the containers so that the drainage pipes are level with the tent's lower openings. Or I could cut new openings. Or I could pressurize the return line. We'll see.

This is going to be a vertical grow with two bare bulbs. I plan to post some sketchup models of the whole system in another thread.

MisterWhilom said:

Hi, folks,

Here are a couple of evolving illustrations of a Waterfall/Top-Feed Recirculating-DWC system I'm designing:

Schematic:

Sketchup model:

I'm personally drawn to the idea of a pressurized feed line for a few reasons:

a) I can take a top feed to a drip ring which will allow me to plant seedlings at the optimal height inside the netpot and feed them around their perimiter, which means I get nice, wide roots, and I don't have to overfill my container.(compared to UC: no built-in top-feed)

b) I can run the whole thing using small, inexpensive, immersible head pumps inside the controller so I only have to plumb one side of the pump. (I'm not worried about res temps till summer, but I have an external pump, too, JIC)

c) Each container requires only one large, pressure-sealed opening (UC = more points of failure, more labour, higher parts cost).

d) Any site can be seamlessly isolated from the system with valves if necessary (UC: impractically difficult to isolate sites).

The Questions:
1) I've compared this method to Undercurrent, and though it seems popular these days, I'm unclear on the benefits of having the return line under pressure rather than the feed. As long as the low-pressure pipes have the passive capacity to keep up with the high-pressure-side flow does it really matter which way we're pumping?

2) Considering the upshots I get from Top-Feed/Waterfall, are there any reasons to keep investigating UC?


Any takers?



\\ /\/\ \/\/ \\

Click to expand...

Hello MisterWhilom.....

I have looked over your design.....and it is alot like I am set up.....I have a control bucket in my tent so I can set my water level, and there is a 60 gallon barrel out side of the tent that is up on some bricks so gravity will keep my control bucket topped off all the time......I have 6 plants that are drinking about 8 gallons per day right now, so you will need a way to keep your control bucket topped off without haveing to make up nutes everyday......So I would add a big nute barrel outside the tent and connect it to your control bucket with a float valve for setting your water level......

I have drip rings in my buckets that run on a air pump, but using a water pump could be good.....I think the air pump is pretty simple and it doesn't mess with my water level like a pump might.......pulling nutes from my control bucket with a small drip line has entered my mind....along with my air pump drip rings.....I just haven't tried it......I am thinking if you are pumping to much from the control bucket you might have different water levels happening.....If the returns are big like your pic's it might not be a problem.......anyway looks good and good luck..............nitro..

nitro harley said:

Hello MisterWhilom.....

I have looked over your design.....and it is alot like I am set up.....I have a control bucket in my tent so I can set my water level, and there is a 60 gallon barrel out side of the tent that is up on some bricks so gravity will keep my control bucket topped off all the time......I have 6 plants that are drinking about 8 gallons per day right now, so you will need a way to keep your control bucket topped off without haveing to make up nutes everyday......So I would add a big nute barrel outside the tent and connect it to your control bucket with a float valve for setting your water level......

I have drip rings in my buckets that run on a air pump, but using a water pump could be good.....I think the air pump is pretty simple and it doesn't mess with my water level like a pump might.......pulling nutes from my control bucket with a small drip line has entered my mind....along with my air pump drip rings.....I just haven't tried it......I am thinking if you are pumping to much from the control bucket you might have different water levels happening.....If the returns are big like your pic's it might not be a problem.......anyway looks good and good luck..............nitro..

Click to expand...

Hey, Nitro,
As it turns out I may have to abandon this design and go with a Multiflow / Ebb & Grow setup this time 'round.
Whatever the case, I'm going to plumb my RO system directly into a plain water res, which will top off the nute res via a simple float valve and flow volume meter.

Thanks for your feedback!

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Hello there, Nice setup have you thought about black pvc? Also What software did you use to generate those bitchin layouts?

You could always put the rez outside of the grow tent.

I have had good luck using risers in the bucket to keep the water level where you want. The water gets pumped in the bottom and drains back to the sump at the level of the risers. Just have to place the res lower than the buckets. This gives you good natural aeration and I put an airstone in each bucket. If your interested ill send you some picks, I'm growing using this method right now. It's simple and expandable.

hey again chris, hope all is well with your design, thanks for answering my questions about the model pics, i was wondering if i could ask a couple more, to make that up do u have any skills or anything lie that in design or with computers and can anyone just buy this ''sketch up'' program or whatever it is and do the things you did in that pic? thanks again for your time, and if u need any help with hydro dont hesitate to ask, im a wealth of information, later

Tricyknome said:

Hello there, Nice setup have you thought about black pvc? Also What software did you use to generate those bitchin layouts?

Click to expand...

Black PVC in what application? Pipes? I'm just using what I can source locally, and that's standard grey, 75mm PVC.

The 3D models were built in Sketchup. The flat schematic was made using Google Drawings.


]-[

aknight3 said:

hey again chris, hope all is well with your design, thanks for answering my questions about the model pics, i was wondering if i could ask a couple more, to make that up do u have any skills or anything lie that in design or with computers and can anyone just buy this ''sketch up'' program or whatever it is and do the things you did in that pic? thanks again for your time, and if u need any help with hydro dont hesitate to ask, im a wealth of information, later

Click to expand...

I'm not quite sure what your question is exactly.

Sketchup is free for anyone to download and use. There's also Sketchup Pro, which costs money.
I used the free version.

As it happens I'm an experienced graphic designer so I have a slight edge on the uninitiated, but anyone with a little tenacity can figure out how to use Sketchup (or any other design software).

Thanks for your offer of help; I hope I can take you up on it someday soon.

BTW, my name's not Chris.

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harvestchris said:

I have had good luck using risers in the bucket to keep the water level where you want. The water gets pumped in the bottom and drains back to the sump at the level of the risers. Just have to place the res lower than the buckets. This gives you good natural aeration and I put an airstone in each bucket. If your interested ill send you some picks, I'm growing using this method right now. It's simple and expandable.

Click to expand...

I've considered using risers to get gravity into the game. Problem is that I'm growing vertically in tents so the higher I raise my plant containers the more surface area I lose. I may I'll start a new thread soon with diagrams so you can visualize it.

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Hello, again "Sketchup" thanks . Black pvc is also called flex pvc, but you probably cant source it locally. i get mine from McMasters supply.

http://www.mcmaster.com/

Great drawing man.
Im just gonna say u can lose alot of work by deleteing the feeder ring and just pop that pipe onto the top of the tubs.
Second even with the waterfall i would still add a good commercial air pump and get air in each tub yes the waterfall will get oxygen in the water but u would be suprised how much air those plants are gonna need especially if u plan on growing monsters in there and thats inevitable to happen either way an ample amount of oxygen is required for maximum growth and optimal plant/water health.
Third honestly i would remote your controller res out of the tent or grow room this will give u the ease of working your controller res without haveing to deal with plants and at the same time help keep temps in ur res more stable and under control plan on it getting hot i dont care how much u cool ur lamps u cant get them cold enuff and in a small space like so u will have heat issues regardless keeping them at a minimal is what your shooting for plan on the battle and be ahead.
I like ur drawing just a little too much extra work with the drip and stuff long as u keep medium your plants are sitting on just damp not overly wet its going tomanipulate the plants to grow roots out to search for the water bringing quicker and more vigorous health.
Most peoples biggest problem getting into hydro is saturateing there beanlings and shocking them right out the gate. Answer is yes there is a such thing as too much water in hydro u just gotta know when to applly that rule...
I could go on all day check out my homemade rdwc thread in this section if u have any questions feel free to holler.

onthedl0008 said:

Great drawing man...

Click to expand...

Thanks, the drawing has come a long way since my first post, as has construction on the system.
I've been too lazy to keep the thread current but I will make a concerted effort to bring it up to date someday soon.

With regard to some of your points:

• I decided against a drip ring after it occurred to me that I can wet the hydroton from beneath by directing the water stream from the pressurized feed line to just skim the bottom of the net pots. This should keep the roots moist enough until they grow out through the air gap and into the solution below.

• Container aeration was left out of the drawing but it's been part of the plan all along. I'm using Alita airstones, incidentally.

• I'm really not worried about res temps until summer hits.
My setup uses tents, each serviced by far-too-powerful a blower, which, in theory, can exchange the air volume about 159 times an hour (less vent and filter losses). Ambient air temperature (day/night) is about 65/55ºF indoors and about 60/50ºF outside and dropping. The plant containers and controller sit upon a cold, tiled concrete floor. I'm keeping a close eye on things so if it turns out to be a problem I'll do something but for now I think I'm good.

Also, I'm toying with the idea of doing a hybrid DWC/Multiflow setup whereby the water is pumped out of the plant containers at night. It won't be hard to set up but it's only speculation at the moment.


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Well I have been following here and there just haven't put in my 2 cents seeing there's enough going around. Really to consider dropping the costs down and just simplicity of finding them any where I would go with regular 2" air stones that are cylindrical or the 4" air stones from walmart. They agitate the water more than any other and get plenty of DO into the water. With keeping that water very agitated in the buckets you will not need to raise or lower the water level. It creates a very fine mist that keeps it perfect in there. With the right stones and pump of course.

The alita air pumps create a lot of heat in the air they put out and the air they create from running. A better pump to look at I heard was the pump master series. I found the AP-100 for like 130 bucks and is good for 10000gals. So it will feed an entire grow rooms needs for most.

Hydroton is also very dirty and not really at the top of the game anymore. lol. If you want try looking into grow stones or even perlite hempy method.

As for temps you do not want to be that cool. Day time temps should be between 71-78 ideally. With the temp dropping for the dark cycle. Which usually when lights go out and ventilation stays on is enough. To cold and you will get hermies.

Oh and to each their own again but I don't really consider that a vertical grow. lol. Vertical is multiplying your given space by growing "multiple" plants above one another to maximize your space. Hanging the bulb in a vertical postion I don't consider vertical growing. I hang my flouro's vertically and sometimes hang my LED vertically pointing it so it towards the plants obviously.