Central Res DWC with 5 Tubs questions

Aviatorshades

Well-Known Member
Hi everybody, I love the site and have so much fun doing this. My most recent "build" is a 17 Gal Tubs (Home Depot Black / Yellow). Hole cut in top and put a netpot in there with some hydroton. Works fantastic. The lid with the netpot works fine, as I have mylar covering the top to reflect upwards.

So my questions are


1. I would like to build a central res. I was thinking of connecting this central res to all the other 5 tubs. so 5 tubs 1 res. This way, as the water levels drop the res will also drop.
2. I was thinking about having the res on the outside of the tent, and then connecting the piping into the tent. I was hoping to run pipes from each tub to each tub, so essentially all the tubs would be connected. If I do multiple strains, could I just pick a PPM for everybody. Like do central res at 5.8/ 650ppm. This way it shouldnt spike too bad for either the PH or PPM right?
3. This would allow me to set a generic PH/PPM for everyone and then check and refill every 3-5 days (obviously dependent on how often they drink.)

am I dumb or onto a good idea?
 

rkymtnman

Well-Known Member
there are pros and cons to running DWC (now) vs RDWC (what you are thinking about). i did multi strains in rdwc and your points about finding a sweet spot for EC/ppm are correct. as long as pH is in range, it's not as much a factor
 

Drop That Sound

Well-Known Member
So you just want to setup an "add back" type of system that is connected to each DWC, likely using gravity with float valves? Also, adjusting the add back solution, so as it slowly replensishes & mixes with the containers, it keeps the PH/EC in check?

I dunno.. Personally, I would just build an under current RDWC with large bulkheads, and recirculate through all of them with an inline pump/filter. You could go a few days without having to do any maintenance, with a big enough external res..
 

amneziaHaze

Well-Known Member
Hi everybody, I love the site and have so much fun doing this. My most recent "build" is a 17 Gal Tubs (Home Depot Black / Yellow). Hole cut in top and put a netpot in there with some hydroton. Works fantastic. The lid with the netpot works fine, as I have mylar covering the top to reflect upwards.

So my questions are


1. I would like to build a central res. I was thinking of connecting this central res to all the other 5 tubs. so 5 tubs 1 res. This way, as the water levels drop the res will also drop.
2. I was thinking about having the res on the outside of the tent, and then connecting the piping into the tent. I was hoping to run pipes from each tub to each tub, so essentially all the tubs would be connected. If I do multiple strains, could I just pick a PPM for everybody. Like do central res at 5.8/ 650ppm. This way it shouldnt spike too bad for either the PH or PPM right?
3. This would allow me to set a generic PH/PPM for everyone and then check and refill every 3-5 days (obviously dependent on how often they drink.)

am I dumb or onto a good idea?
my current grow one strain is at 770 other is at 920.... i would stick to same strain if you do one res. i even have same strain in one tub but one is a lot smaller and she doesnt like the same ppm
 

Aviatorshades

Well-Known Member
Anyways.. ya you should build one! If you need help lemme know, I can tell you how to make the best systems from scratch, for pennies on the dollar ;)

View attachment 5264532
Yeah I was thinking the bulk head route. I just don't have a chiller for the pumps and worry I would need one. Hoping not. Would love more tips and tricks from ya. I figure I'll put a plastic mesh screen over each inlet/outlet at the bulkhead to make sure no roots get clogged into it. We all know how crazy roots get! Lol
 

Treesomewanted77

Well-Known Member
Yeah I was thinking the bulk head route. I just don't have a chiller for the pumps and worry I would need one. Hoping not. Would love more tips and tricks from ya. I figure I'll put a plastic mesh screen over each inlet/outlet at the bulkhead to make sure no roots get clogged into it. We all know how crazy roots get! Lol
The roots will still get through a screen so make sure you use like 3” pipe to connect the tubs is the best bet. PA hydroponics makes some nice systems just like drop posted and they do videos on how to build them DIY.
 

breedwheel

Well-Known Member
Yeah I was thinking the bulk head route. I just don't have a chiller for the pumps and worry I would need one. Hoping not. Would love more tips and tricks from ya. I figure I'll put a plastic mesh screen over each inlet/outlet at the bulkhead to make sure no roots get clogged into it. We all know how crazy roots get! Lol
 

breedwheel

Well-Known Member
Yeah I was thinking the bulk head route. I just don't have a chiller for the pumps and worry I would need one. Hoping not. Would love more tips and tricks from ya. I figure I'll put a plastic mesh screen over each inlet/outlet at the bulkhead to make sure no roots get clogged into it. We all know how crazy roots get! Lol
Chiller is a big investment. Putting the reservoir outside the tent will help keep your water temps down a lot. If you can keep your pump outside your reservoirs this will also help with water temps. Water temps were always my biggest hurdle with RDWC. I agree about not trying multiple strains. Minimum 2" pipes 3" is better. The screens didn't work for me.
 

Drop That Sound

Well-Known Member
Ya what you described was basically RDWC without the R. Just hooking DWC buckets together, which technically could work like you said, but not the way you want.. You want it to circulate and constantly be mixed up, keeping the water from stagnating in any way. If you need a chiller, it will chill all the buckets while recircing too. You would be better off to just use one large 50 gallon DWC tote with multiple net pots than to hook a bunch of smaller 17 gals together with out a water pump.

Add a pump that pulls everything back to the res though, and more bulkheads on both sides of containers with some pipe, and now you have a recirculating RDCW system. Inline pumps are better IMO because they can be externally installed, so they don't heat up the water as much. You need an inline y-strainer/filter though for the inline pump..

If you submerge the pump, you can simply drop it in a mesh filter bag to keep it from clogging. Save a bit of money. I suggest buying an ecoplus 396 fixed flow pump for $28, that can also be submerged in a cheap filter bag until you can afford a larger 2" Banjo brand y-strainer, that is 3 times bigger than the 3/4" dripper y-filters at home depot, and won't clog as quickly the smaller ones do..

For sure the minimum size for the bulkheads and manifolds should be 2". You'll notice its gonna cost a fortune to buy them. It doesn't have to though. I make mine for less than $3 a piece, with 3 simple parts. A size 331 o-ring, and both male and female electrical PVC conduit terminal fittings. Undercurrent system is the way to go. Don't use tiny fittings for anything, other than the main return line from the pump back to the res. It should be 1" at the least too..
 

Actinolite

Member
Yeah I was thinking the bulk head route. I just don't have a chiller for the pumps and worry I would need one. Hoping not. Would love more tips and tricks from ya. I figure I'll put a plastic mesh screen over each inlet/outlet at the bulkhead to make sure no roots get clogged into it. We all know how crazy roots get! Lol
imo putting screens in to block roots causes more problems than it's worth. the roots will just grow in to the screen and turn it in to a wad of roots. you're better off either using large enough piping that the roots won't be an issue or just pulling them out of the pipes every few weeks.
also if you do use screens don't use copper ones, people will suggest the copper will prevent roots from growing on them but copper likes to react with your nutrient solution and can cause other issues
 

Drop That Sound

Well-Known Member
Tip: If I did for some reason have to trim up overgrown roots in a container that are snaking their way into the pipes, I just temporarily rubber band a mesh filter bag over the inside fitting of the next bulkhead, in the next container downstream. It will catch most anything that doesn't get pulled out by hand. Then pull it out after I swirl the container around, trying to get any debri stirred up into the flow.

Even if I missed something, the banjo y-strainers will always keep it from clogging the pump.

You can make your own filters and save money too. Could be as simple as adding another smaller container before the pump (with no plant) , and putting a filter bag inside, just like I described above.
 

Aviatorshades

Well-Known Member
Ya what you described was basically RDWC without the R. Just hooking DWC buckets together, which technically could work like you said, but not the way you want.. You want it to circulate and constantly be mixed up, keeping the water from stagnating in any way. If you need a chiller, it will chill all the buckets while recircing too. You would be better off to just use one large 50 gallon DWC tote with multiple net pots than to hook a bunch of smaller 17 gals together with out a water pump.

Add a pump that pulls everything back to the res though, and more bulkheads on both sides of containers with some pipe, and now you have a recirculating RDCW system. Inline pumps are better IMO because they can be externally installed, so they don't heat up the water as much. You need an inline y-strainer/filter though for the inline pump..

If you submerge the pump, you can simply drop it in a mesh filter bag to keep it from clogging. Save a bit of money. I suggest buying an ecoplus 396 fixed flow pump for $28, that can also be submerged in a cheap filter bag until you can afford a larger 2" Banjo brand y-strainer, that is 3 times bigger than the 3/4" dripper y-filters at home depot, and won't clog as quickly the smaller ones do..

For sure the minimum size for the bulkheads and manifolds should be 2". You'll notice its gonna cost a fortune to buy them. It doesn't have to though. I make mine for less than $3 a piece, with 3 simple parts. A size 331 o-ring, and both male and female electrical PVC conduit terminal fittings. Undercurrent system is the way to go. Don't use tiny fittings for anything, other than the main return line from the pump back to the res. It should be 1" at the least too..
How would I have stagnant water if I have bubblers in each tub?
 

Drop That Sound

Well-Known Member
Mostly in the plumbing. Trust me, it will possibly grow scum, or create an environment to harbor pathogens in any of the the tubes you got coming off the containers like that. Even short runs of larger diameter pvc pipes between them. Not enough dissolved oxygen gets in there with just air pumps alone. The main area of the tub, yes it works fine. Thats why DWC works so well. Because its kept simple, and easy to clean the buckets out.

It's like when you add a small tube off the side of a DWC container, for pumping in/out nute solution, or god forbid, you want to see the water level through it like an indicator, using a clear tube... Nasties always end up accumulating in all the nooks and crannies like that, even if your pumping a ton of air, and using the tube every few days.. Just isn't enough to circulate the water. . Especially if your solution is warm, look out! It will do a decent job over all, in the main area, don't get me wrong..

You would need a pump just to circulate in each tub to be safe, so you might as well use one pump and do them all, right?. RDWC allows you to run continous low ppms of chlorine too, and will keep the system pretty clean, going way longer without having to break down and do a full cleanout. Might get away without a chiller that way too.

You don't wan't add back for each tub. Or to have to manually adjust multiples of anything. That's too many float valves to deal with, and higher odds one could fail. You want RDWC system, with one top off system going to your main res. You could use that one top off to have more control over the PH, without needing a sophisticated auto dosing system. For example, if you know your PH will rise, you add a little extra PH down to the add back solution. It can be tricky to get the hang of it though, and dial it in.
 
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