RDWC: Rules of thumb?

Inazad

Well-Known Member
Hi there,

I'm thinking of upgrading my current DWC setup that I have to a RDWC.

I currently have 4 buckets of 4 gal each.

I am wondering how to setup the return/main lines sizes and which type of material I should use.

I need to keep in mind that if I want to add 2 more buckets for the next grow, I will be able, I don't want a full permanent system.

Does it will be good to use 1/2 po PEX for the main line (from the pump) and using 1 1/2 po for the return line (abs/pvc) ?

Do I will have circulation problem ?

Which water pump size I should need ?

I have a 4 x 4 space for that. The rez will be outside of the growing space.
 
I don't know if it will works but I want a setup like this. (see picture) don't know if its good ?

Does the rez should have the same size of the buckets ? cause I have 4 gal buckets, I should have a 4 gal rez ?

I drawed a plan, does it will works ? does the water will flow correctly to the rez ?

The blue line will be 1/2" pex tubing, gray line are return lines (pvc/abs 1 1/2 ").

Cause I want a system that I can add 2-4 buckets anytime without cutting a lot of pipes...
 

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From your plan it looks like you’re doing a waterfall style. One problem I see is your putting the fresh water in right over the top of where it’s going to drain back to the reservoir. This will create stale spots in the grow buckets. It will work better if you run the fill lines in the opposite sides of the buckets as the returns. I would suggest also running an inline pump outside of the reservoir to help eliminate adding extra heat to the nutrient solution. The bigger the return lines the better to avoid clogging them with roots. 2” would be the minimum I’d go with.
 
Cause I want a system that I can add 2-4 buckets anytime without cutting a lot of pipes...

On the last 2 buckets, don't use a T for the return. Use a cross instead and add a little bit of pipe, then cap it. Voila. Easy extension. You may be able to use a cap/plug directly into the open end of the cross as well. Makes for an easy extension of buckets if you want.


The bigger the return lines the better to avoid clogging them with roots. 2” would be the minimum I’d go with.

^^ This.
 
If you’ve already bought one I’d go ahead and use it. Just monitor your water temp. The ideal water temp is 68F. If you start getting into the high 70’s you’ll run the risk of serious problems.
 
Where I can take a cross for the last 2 buckets ? I only found Tee. and which connectors do you propose to me ?

So if I resume,
  • the top main line will be 1/2" in PEX
  • the return line will be 2" in PVC / ABS
  • each buckets will have a 2" uniseal
  • the water pump will be in the rez (and verify the temp is < 68F)
 
There is my air pump and water pump, does the gallon per hour is enough ? does it too high ?

Air pump 1110 gph
Water pump is 920 gph
 
Where I can take a cross for the last 2 buckets ? I only found Tee. and which connectors do you propose to me ?

So if I resume,
  • the top main line will be 1/2" in PEX
  • the return line will be 2" in PVC / ABS
  • each buckets will have a 2" uniseal
  • the water pump will be in the rez (and verify the temp is < 68F)


The following link is an example of a cross fitting:



That's the kind of thing to look for.

One return line, 2 buckets connect to each cross (on left and right sides) while the main return connects into the top/bottom.

The last pair of buckets, you obviously wouldn't have a continuing main return. This is where the plug would go, and there are several ways to do it.
 
and for the main line tubing in pex, where I can find tees and cross to do the same ?

for the rez, how I can cold the rez if his getting too hot ?
 
Your local hardware store should sell pex and accessories. You don’t have to use pex either. That black plastic tubing(not sure what it’s called) I see a lot of people use. I use all pvc on mine.

You can buy a water chiller to keep your res cool. Google search water chillers and there are plenty of options. I have a 1/10 HP chiller and it’s works great for about 20 gallons. I’m sure it’d be sufficient for more. You’ll need a separate pump if you decide to run a chiller though.
 
I'm asking what should be the size of the rez? I got 4 gal buckets to grow my ladies.

Also, which tubing I should use for my water pump (main line) ? I got a 0.5" and a 0.75" outlet, which should I take ? (water pump is > 900 gph).

How do you use PVC with your water pump ?
 
A picture worth a thousand words
2FC49A78-1312-43D5-824E-73D9CDD5F597.jpeg


As for the supply line. I doubt it’ll matter whether it’s 3/4 or 1/2. I’d go 1/2 cause it’s cheaper and you’ll get a higher velocity to create more dissolved oxygen when it hits the water in the grow buckets

As for the res size. It’s up to you. Some people like a large res to add stability in ph. I don’t use a large one. It’s mostly just a convenience in adding nutrient solution. And if you’re using a tent or have the ability with you space, you can locate the res outside your grow area to reduce heat in the water and make it even easier to change the solution.
 
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