Big Scale RDWC System

[kumar69]

Ladies and Gentlemen,

I have a dilemma before I invest shit load of money, so I would like to ask your opinions about it. I would like to build a recirculating DWC system in a big scale. Instead of buckets, I would use long discharge pipes. Each pipe would be 410 cm (13.5 feet) long, and there would be 16 pipes total. The pipe diameter is 160 mm (6.3 inch). I would use 5 cm (2 inch) deep netcups with a collar to hold the plant. The water level in the pipes would be 9-10 cm (3.5 - 4 inch), so it gives 1-2 cm (0.4 - 0.8 inch) gap between the water and the bottom of the netcups. From the pipes the water would run into one big control reservoir tank, where I put airstones for DO. The pump would run 24 hours a day and pumps back the water to the pipes. I hope you understand how I imagine it, see attached drawing.

- According to the calculations, the amount of the water JUST in the pipes would be 867 liters (229 gal). How big control tank I'll need for this amount of water? I would change the full tank of water+nutes in the CONTROL tank once a week, while leaving the standing water in the pipes. I set the pH to 5.8 and then I don't want to adjust pH between those water changes. I'm guessing 2000 liters (528 gal) would be fine to avoid pH swings and enough nutes for a week? Therefore I have 867+2000 liters (758 gal) mixing and running around for a week.

- Those pipes are wide enough, or may I go for a wider? The next step is 200 mm (7.9 inch) diameter, but in that case the water consumption would be even way more.

- The water flow speed would be something like 1-2 liters (0.25 - 0.5 gal) per minute per pipe, is that enough?

- Water temperature 20 Celsius or 68 Fahrenheit. Good?

If you have any opinions or advice for this system, please share it too.

Thank you

 

[rkymtnman]

it's basically the same as a GH aeroflo unit but on a bigger scale.

 

[redi jedi]

Why pipe for the plant sites. Even 6" pipe is still a small space for roots and it costs ALOT. You could do the exact same thing with totes. Working with a flat lid for netpots is much easier too.

 

[kumar69]

Why pipe for the plant sites. Even 6" pipe is still a small space for roots and it costs ALOT. You could do the exact same thing with totes. Working with a flat lid for netpots is much easier too.

You mean Tote boxes like this?
https://www.bigdug.co.uk/mega-deals-c411/bigdug-tote-box-mega-deal-p17041/s39131?cid=GBP
If so, it would costs way more and I can't imagine the water consuption

 

[Mellow old School]

Depending on where you live, you can in Europe eg. get drainage pipes with a width of 16 cm/6,2 inches, for not alot of money, they can hold quite a bit of roots and water.

 

[kumar69]

Depending on where you live, you can in Europe eg. get drainage pipes with a width of 16 cm/6,2 inches, for not alot of money, they can hold quite a bit of roots and water.

This is exactly the pipe I'm concerning about. They sell it here in 5 meters lenght pieces for like 20 bucks. How about the control tank size?

 

[mr4tune]

I started out with a DIY version of the aeroflo and came up with these...



A few years later I built this in one of the rooms...



Anywho heres my 2 cents on it... I didn't go the RDWC route, it was more of an NFT/LP Aero setup. These systems used to be the tits back in the day for a few of us, but not many guys running them anymore it seems like. I did 360 degree sprayers between each pot pumping from barrels in the adjacent water room where it traveled down each length and was returned to the res. Same as an aeroflo only way bigger.

Idk what your situation is but coco would be damn near as fast and there's no need for chillers, pumps, or the risk of root rot. You also want to separate the systems in case you have a bacteria issue you don't lose the entire place. Once you separate them you then need more pumps, chillers, etc. for each system which adds to the cost. With my setup if I had a pump shit the bed I'd have a completely crop loss in no time but I was there 24/7. Obviously thats not an issue if you have a set water level.

Fernco makes the end caps and they are expensive. The bigger the pipe the better. 6" is fine for a small setup but you don't have allot of wiggle room on your veg size. But again, depending on the space between pot sites its doable. I'd strongly recommend 8" or higher just to be safe. then you can also increase your netpot size if needed. Only draw back is as soon as you go above 6" you go from municipal sewer/water to an industrial end cap and the price skyrockets. Since you need x2 per tube....

The tubes plug up with roots extremely fast which makes for uneven circulation when it comes to the drains. Regardless of whether you are flooding the tubes or not. If your wanting to go RDWC then this is even worse than with my tubes since id have a pile of time to catch it since i had a stream travelling. With your design, if your drain plugs in you'll flood the place out.

You had also obviously better have a real good grasp before hand on hydro and have a proven method for dealing with bacteria. I preach sterile systems all the time, I'm sure its getting old so I'll skip that part.

They are good systems but given the cost and potential for issues I really think coco is the way to go. I'm running a couple undercurrent systems now and as cool as they are, theres allot of extra bullshit in the mix whereas I could get almost the same results from multifeed coco with waaaay less potential points of failure.

Best of luck, DM me if you have any questions I might be able to help out with.

 

[kumar69]

I started out with a DIY version of the aeroflo and came up with these...

View attachment 4803941

A few years later I built this in one of the rooms...

View attachment 4803943

Anywho heres my 2 cents on it... I didn't go the RDWC route, it was more of an NFT/LP Aero setup. These systems used to be the tits back in the day for a few of us, but not many guys running them anymore it seems like. I did 360 degree sprayers between each pot pumping from barrels in the adjacent water room where it traveled down each length and was returned to the res. Same as an aeroflo only way bigger.

Idk what your situation is but coco would be damn near as fast and there's no need for chillers, pumps, or the risk of root rot. You also want to separate the systems in case you have a bacteria issue you don't lose the entire place. Once you separate them you then need more pumps, chillers, etc. for each system which adds to the cost. With my setup if I had a pump shit the bed I'd have a completely crop loss in no time but I was there 24/7. Obviously thats not an issue if you have a set water level.

Fernco makes the end caps and they are expensive. The bigger the pipe the better. 6" is fine for a small setup but you don't have allot of wiggle room on your veg size. But again, depending on the space between pot sites its doable. I'd strongly recommend 8" or higher just to be safe. then you can also increase your netpot size if needed. Only draw back is as soon as you go above 6" you go from municipal sewer/water to an industrial end cap and the price skyrockets. Since you need x2 per tube....

The tubes plug up with roots extremely fast which makes for uneven circulation when it comes to the drains. Regardless of whether you are flooding the tubes or not. If your wanting to go RDWC then this is even worse than with my tubes since id have a pile of time to catch it since i had a stream travelling. With your design, if your drain plugs in you'll flood the place out.

You had also obviously better have a real good grasp before hand on hydro and have a proven method for dealing with bacteria. I preach sterile systems all the time, I'm sure its getting old so I'll skip that part.

They are good systems but given the cost and potential for issues I really think coco is the way to go. I'm running a couple undercurrent systems now and as cool as they are, theres allot of extra bullshit in the mix whereas I could get almost the same results from multifeed coco with waaaay less potential points of failure.

Best of luck, DM me if you have any questions I might be able to help out with.

Thank you Mister, that's well explained. Your setup looks neat! The idea to keep the water level high is because of exactly what you said: if a pump fails, there are still backup nutes for them in the pipe. Plus the roots are very well marinated, no need 200 sprayer heads. I personally like coco very much too, my pepper plants are in it. But in the location of the hydro garden is, it's a pain in the ass to bring in an out coco or any kinda growing media. While to get rid of the used drain in RDWC, I just press a button and the pump pushes it out. I have RO water, I think I could keep the system sterile. That's why I'm considering this. Currently I run a prototype but a 8" pipe, and everyone looks happy (2nd week of 12/12). Though I set the water level pretty low (less than half of the pipe). That's what I want to change. Bit narrower pipe, higher water level. I still can't imagine the root could block the drainhole completely. But it's a good thing to think about it.

 

[mr4tune]

Ahhh copy that man.

I just see the flaw being the lack of air within the tubes with how you have it setup right now. No offense, just something to consider. I could be wrong...

Look at any rdwc system and they either use a waterfall effect into each bucket or and airstone in each. I'd think you'd be better off having some airstones within the tubes themselves to keep the water within agitated and to add fresh air inside. You'll have the waterfall effect going into your reservoir just from the drain itself. I'd lay money down that you'd have allot more lateral root branching above your waterline if you did it this way. Use up that space since its limited. How it is right now you can see your roots are going straight down and there isn't many of those fuzzy roots that catch up the high DO level nutrients within the air.

As far as the roots, they dont need to block it completely.... It only takes enough so that the input is higher than the output and its gonna get wet.

On a final point RO has zero to do with bacteria. If you aren't running a chlorine product or something like hydrogaurd (if thats your thing), consider yourself blessed for not having issues by now lol. Once you have a pile of light above those tubes internal temp comes into play. At least it did with my 1k DE's.

1000 ways to skin a cat anywho

 

[H1ghTime]

I started out with a DIY version of the aeroflo and came up with these...

View attachment 4803941

A few years later I built this in one of the rooms...

View attachment 4803943

Anywho heres my 2 cents on it... I didn't go the RDWC route, it was more of an NFT/LP Aero setup. These systems used to be the tits back in the day for a few of us, but not many guys running them anymore it seems like. I did 360 degree sprayers between each pot pumping from barrels in the adjacent water room where it traveled down each length and was returned to the res. Same as an aeroflo only way bigger.

Idk what your situation is but coco would be damn near as fast and there's no need for chillers, pumps, or the risk of root rot. You also want to separate the systems in case you have a bacteria issue you don't lose the entire place. Once you separate them you then need more pumps, chillers, etc. for each system which adds to the cost. With my setup if I had a pump shit the bed I'd have a completely crop loss in no time but I was there 24/7. Obviously thats not an issue if you have a set water level.

Fernco makes the end caps and they are expensive. The bigger the pipe the better. 6" is fine for a small setup but you don't have allot of wiggle room on your veg size. But again, depending on the space between pot sites its doable. I'd strongly recommend 8" or higher just to be safe. then you can also increase your netpot size if needed. Only draw back is as soon as you go above 6" you go from municipal sewer/water to an industrial end cap and the price skyrockets. Since you need x2 per tube....

The tubes plug up with roots extremely fast which makes for uneven circulation when it comes to the drains. Regardless of whether you are flooding the tubes or not. If your wanting to go RDWC then this is even worse than with my tubes since id have a pile of time to catch it since i had a stream travelling. With your design, if your drain plugs in you'll flood the place out.

You had also obviously better have a real good grasp before hand on hydro and have a proven method for dealing with bacteria. I preach sterile systems all the time, I'm sure its getting old so I'll skip that part.

They are good systems but given the cost and potential for issues I really think coco is the way to go. I'm running a couple undercurrent systems now and as cool as they are, theres allot of extra bullshit in the mix whereas I could get almost the same results from multifeed coco with waaaay less potential points of failure.

Best of luck, DM me if you have any questions I might be able to help out with.

I like your set up, i've been debating whether i go with a set up like that,. do you have any pics of set up inside the tubing?

 

[mr4tune]

I like your set up, i've been debating whether i go with a set up like that,. do you have any pics of set up inside the tubing?

I have a bunch of em on the old laptop i think. Ill see if I can dig some up for you.

 

[redi jedi]

You mean Tote boxes like this?
https://www.bigdug.co.uk/mega-deals-c411/bigdug-tote-box-mega-deal-p17041/s39131?cid=GBP
If so, it would costs way more and I can't imagine the water consuption

Well I guess pvc pipe is extremely cheap in the UK...3" sch 40 pvc is 50 bucks cdn for 3 meters, 10 footer...anyways, theres a reason you dont see people running flooded tube anymore.
Water consumption wouldnt change much from one system to the next given the same amount of plants and veg time.

 

[redi jedi]

Depending on where you live, you can in Europe eg. get drainage pipes with a width of 16 cm/6,2 inches, for not alot of money, they can hold quite a bit of roots and water.

Not alot of money?...maybe if your paying some kid to nick it from a construction site...lol

 

[kumar69]

Ahhh copy that man.

I just see the flaw being the lack of air within the tubes with how you have it setup right now. No offense, just something to consider. I could be wrong...

Look at any rdwc system and they either use a waterfall effect into each bucket or and airstone in each. I'd think you'd be better off having some airstones within the tubes themselves to keep the water within agitated and to add fresh air inside. You'll have the waterfall effect going into your reservoir just from the drain itself. I'd lay money down that you'd have allot more lateral root branching above your waterline if you did it this way. Use up that space since its limited. How it is right now you can see your roots are going straight down and there isn't many of those fuzzy roots that catch up the high DO level nutrients within the air.

As far as the roots, they dont need to block it completely.... It only takes enough so that the input is higher than the output and its gonna get wet.

On a final point RO has zero to do with bacteria. If you aren't running a chlorine product or something like hydrogaurd (if thats your thing), consider yourself blessed for not having issues by now lol. Once you have a pile of light above those tubes internal temp comes into play. At least it did with my 1k DE's.

1000 ways to skin a cat anywho

Okey, completely makes sense. That means I need a big drain hole (10 cm diameter) which I have to check time to time. If there are plenty of roots inside, just prune it? I draw it, this could work?

Dissolved Oxigen is a great point, wanted to ask that too, just forgot. The water falls to the control tank, and there are lots of airstones. I can put there as much as it's needed. Plus, there is a gap between the netcups and water level. Kratky also doesn't use airstones, right? Well, if it's neccessary I can put some airstones into the pipes, I just wanted not to

Yes, I'll use the space more, this is just a prototype. As I said, a bit smaller pipe, but higher water level.

Thanks!

 

[kumar69]

Not alot of money?...maybe if your paying some kid to nick it from a construction site...lol

I just checked. PVC KG drainage pipe (which can even hold pressure underground) is 30 USD for a 5 meter (16.4 foot) long piece, 160 mm diameter (6.3 inch). I'll need 16 pieces (for 200 plants), so it's 480 USD total. I'm not sure how to make it cheaper with separate totes or buckets, plus the connector and drain pipes. Plus all the hassle...

 

[Mellow old School]

Yes I can read that you dont care for the pipe idea, I would say bot with buckets and/or pipes there will be some work/hassle in volved in the project.

Expensive is relative, I dont think you can buy buckets are that much cheaper in total then the pipes. You can build a system of that size alot cheaper than eg. to buy the org. AeroFlo, instead of those small sprayers as on the AF and the other DIY system shown above I changed mine to waterfalls in the pipes with parts from the GHE WaterFarm systems.

If you have waterfalls instead of the smaller sprayers you dont need as many. I have experienced if the pump is powerfull enough, one waterfall in the end opposite the drain is enough, in the case of the 16,4 foot, I would think 1 in the end and 1 in the middle will give quite a good flow through the whole pipe.

Regarding the reservoir or reservoirs depending on the size of a system, I have used between 1-5 us gallons pr plant in the past. I would choose several reservoir connected together when having so many plants.

This is a very small version system I use in a closet, with a bit smaller pipe 11cm/4,2 inches.



But opinions are like a-holes everyone has one...

Have a good Weekend.

 

[redi jedi]

I just checked. PVC KG drainage pipe (which can even hold pressure underground) is 30 USD for a 5 meter (16.4 foot) long piece, 160 mm diameter (6.3 inch). I'll need 16 pieces (for 200 plants), so it's 480 USD total. I'm not sure how to make it cheaper with separate totes or buckets, plus the connector and drain pipes. Plus all the hassle...

Pvc KG? Anyways....if your heart is set on using sewer pipe, go nuts. And if you think your gonna buy 16 peices at 30 usd I would suggest you find a supplier and actually call them for a quote. Since the people that buy pipe like that are contractors building sewers for a municipality, you might find thats the price when buying several kilometers of pipe!

 

[kumar69]

Pvc KG? Anyways....if your heart is set on using sewer pipe, go nuts. And if you think your gonna buy 16 peices at 30 usd I would suggest you find a supplier and actually call them for a quote. Since the people that buy pipe like that are contractors building sewers for a municipality, you might find thats the price when buying several kilometers of pipe!

I called one of the shop, that's what they said. The brown one, 5 meter long, 160 mm diameters. 30 usd. I don't really want to argue on that

 

[kumar69]

How about the control tank size at this RDWC? 2000 liters would do the job if I have 900ish Liters in the pipes? Thanks

 

[redi jedi]

How about the control tank size at this RDWC? 2000 liters would do the job if I have 900ish Liters in the pipes? Thanks

Sure, thats a big tank or two but you dont have to fill it I guess...