So Ive been designing a RDWC and just wanted to see what you think and if it would work. All lines would be 3/4 inch garden hose and PVC fittings so I have some flexibility in the system as well as the ability to expand it as needed. I also want to use the hose so when it comes time to do a water change and can hook the lower hose (feed line) up to the return on the res and use the pump to push the water to the tub. I and going to use a 1000 watt HPS and 4 inch net pots. My tubs Im still debating on but I will prob use a 10 gal sterlite. Top view. The black box is the pump. I only showed the plumbing for the feed side but the return would be similar Side view
It's a bit difficult to understand your drawings... In theory, yes, this could be made to work... One of the best features of it, IMHO is the "waterfall" that would take place due to the return nutrients falling into the large reservoir. This will help the water trap dissolved oxygen in the solution. However, what you'll need to be aware of is: 1) that pump will always add heat to the water, heat is the #1 enemy in any DWC (recirculating or not) So you need to control the heat. (see my article about root rot, and lack of oxygen due to heat here) I've had success in RDWC systems by using a water chiller. (See my thread about DIY RDWC system on these forums here) 2) You're gonna need a big pump, because that's a tremendous amount of head pressure based on your drawings. Big pumps mean you need big pipes too. 3) You'll need a LOT of bubble injected into that system including the reservoir and each plant site (at least 2 watts of airpump power per gallon of nutrient solution) 4) The general flow of fluid dynamics seems strange. I think you'd be better off losing the 4 ways , and pump into the back two buckets, allowing them to overflow into the front two buckets, which would overflow into the res.... If you ever get a blockage in that system, it's going to turn into a huge mess. 5) flow flow flow, RDWC needs a lot of flow to be truly effective. This system is too restricted to have that much flow. Take a look at the Undercurrent systems, and my article about the DIY RDWC, it's a superior design. You can make something like this work well enough to grow plants, but you're gonna have a lot of headaches with it. You're going to be fighting with physics, rather than leveraging it, and that's just a waste of energy.
Thank you for the input. alot of the marks you see are ball valves so that I can shut off individual tubs. The idea was to have a "waterfall" to aid in oxygenation. I dont show it in the drawings but every tub would have an air stone as well as stones in the res. 1 I do intend on getting a water chiller once I can afford one. 2 I do plan on getting a large pump to move the water. In a 3/4 in pipe at 80 psi I can move 150ish GPM 3 I knew I had to put out alot of air but wasnt aware of the watts pr gal. Part of the design is to allow it to re-oxygenate itself 4 My thoughts were with it pushing water in the bottom it will keep it from getting clogged. If I need to I can put a screen up to keep parts from clogging the return if it becomes a problem. Thats also why I planned on building like this so I can take parts apart as needed. 5 As long as I get a good pump I thought I would be ok. What i figured was at 80 psi a 3/4 in pipe can move around 150 gpm
I prefer overflow systems to undercurrent systems. The problem with undercurrent is if you ever had a leak the pump will empty out all the reservoirs and the plants would soon dry up and die. Overflow system keeps the waterline at the same level all of the time and if there was ever a leak the plants are left with their own full reservoir each
The setup I was working on is kind of a mix of the 2. It would pump the water in the bottomand alow it to return via gravity fed overflow. The main thing I'm worried about is will I be able to flow enough back without upgrading the lines too much as the suply would be pressurized from the pump
If you have undercurrent tubes it doesn't matter if you have overflow as well, it's still undercurrent. Overflow relies on not having any other in or outlets Have your returns twice as wide as your feeds. That way the bore will have 4 times the area to allow free flow easily