hmmmm....
Link was posted funny. you may have to cut and paste instead.
www.marmalade.thruhere.net/DWC
Ah! I see I entered the anchor reference incorrectly in the first post. this one should work.

Nice system, but it's more of a combination between aeroponics and DWC, isn't it? Classic DWC is just aerated water that the roots grow down into, right?

I'm not criticizing or anything, it's just that when I've seen this combination of method before it's been called an aeroponics system, and then people have said it's not "true" aeroponics because the roots dangle into the reservoir.

I like your design, though. It'd definitely work better for some plants than a regular deep water culture system would.

yeah, a friend and I had that same discussion just the other day. I think its more DWC because once the plants gets some substantial roots, they're more imersed in the nutrient than sprayed by it.
I suspect with four holes and a 360° sprayer, you could probably grow 4 peppers with it and they'd be growing in a more aeroponic manner.

Please don't take this as critisizm of the design. But, it seems that the cost ratio is high for a single plant. I would take the pump out of the 5 gallon bucket and put it in a 30 gal trash can. Next, I would redo the piping so that the output of the pump would deliver the pressurized water to perhaps a dozen 5 gal buckets or more/ Install a float switch in the 30 gal trash can to shut down the pump when the level goes down too low. It might be worth while to add a second pump to eliminate the need to have the pails elivated for gravity flow return of the neutrients, but no big deal there as you could always half bury the 30 gal trash can to make it lower than the growing stations. Hope that this gives you something to consider, chuck

Criticism is always welcome. I use this design to grow plants in an office window. I could easily grow 2 tomatoes or 4 peppers, but that'd be maxing out the available lid area.
My pump only runs about $15. that size pump will not run a dozen sprayers. The cost ratio may be high, but initial cost is minimal. My system is more of an introductory system or for people on limited space. That being said, you could increase your yields by using a larger container. say one of those 18x24 -ish rubbermaid tubs. That's give you more surface area. maybe grow 6-8 plants and would make lettuces and herbs an option.

I might try a daisy chain of the 5 gallon pails using a larger pump. The 5 gallon size seems ideal for a single tomato plant. Also, the wire plant supports available here fit over a 5 gallon pail very well. Post some operational pictures and some pumping times when you get a chance. What timer are you using? I am working on putting together an inexpensive interval timer. How do you think an on time of several minutes to an off time of 15 minutes might work out in a system like yours? Perhaps someone reading this thread might have some information on a good timing ratio for the pump. chuck

I am using an intermatic programable timer. Currently, on my outdoor system, I'm running 40minutes on and 30 minutes off from 6:00 am to 8:30 pm, then a 30 minute blast around 2:00 am. As the root system grows into the solution, I might increase the 'off' time and decrease the 'on' time.
When I ran this system last year, I basically ran 'on' for about an hour, then 'off' for about 45 minutes. This was basically a function of the timer. with only 14 programs per day, you're working on a 1 hour 45 minute increment. Since reducing my waterings at night, I've changed that increment to 1 hour 10 minutes. Ideally, I would probably like to have 10 minutes 'on' and 30 minutes 'off' but that would require I run two timers in parallel and I'm not that committed yet.
{{gwi:999342}} is a picture of the plant I grew last year.

You're right about requiring two timers. I looked at an intermatic light timer that has 48 event changes per day giving 30 min on/off periods. It's around $9 dollars. With a little relay logic and an ABB delay on make timer, ($21 dollars), the pump on time could be set anywhere from 1 to 10 min per 30 min cycle, which is probably a reasonable range for the vertical grower I'm working on. I might utilize the same controller to also control a number of the 5 gal pails. That was a nice happy looking tomato plant. Were you using the same type of system? Thanks for sharing the timing information. I have a nice omron dual timer, but I'm already using it on another project. chuck

Here is a link that might be useful: vertical grower

It was the same principle but with a few differences. That system didn't have the bottom drain hole. Big pain draining nutes, let me tell ya.
It had more holes in the lid and a 360° sprayer too. There was often a little spray leakage out the top. Not really a problem, but chrystalized nutrient just makes the whole thing look messy.
Also, on the pump I was using then, I had removed the venturi inlet so I had to supplement the reservoir with an air stone.

If you get the kinks worked out on that relay you mentioned, how about posting a little how-to on how to make one. I find circuits incredibly interesting and think they'd be useful for things like what you're talking about.

OH sure grizzman. I've been a ham radio operator for many years, and used to do marine electronics, so I'm always messing with various ideas for timing and control. I was thinking of using a 2 liter bottle on the top of my sprayer to hold nutrients. When the pump turns on, some water pressure will build up in the inverted 2 liter bottle. If there is a slight delay between pulses of water pressure, it will cause a small portion of the nutrients to push out of the 2 kiter bottle and mix with the water going to the sprayer head. I am thinking of using a cheap pressure switch, like the ones used on engines to warn of low oil pressure, in series with the coil of the pump relay. When the pressure goes above around 13psi, the pump relay coil will open, and the pump will stop. Just as soon as the pump stops, the pressure switch will close again turning the pump back on again. The result should be a rapid pulsing of the system for a while until the auxilary bypass timer in the ABB timer switch times out and shunts the water pressure switch out of the circuit. The aux timer switch is built into the main timer which is adjustable up to 10 min. The aux timer is pre-set for 5 seconds. So the net result should be 5 seconds of rapid pulsing to milk the neutrient bottle of some plant food followed by 1 to 10 min of continous water spray. I haven't tried it yet, but it should work. The ABB timmer is $21.95. I probably will just try something easier first, but it was kind of intresting to think about. chuck

I had to read it 3 times, but it finally makes sense.
Aren't automotive oil pressure switches DC? how do you combine it with an AC system or were you just using that as an example?
I suppose you could find a similar switch that runs in AC, right?
Thanks for laying it out so simply.

I'd love to see some pictures of that design. I'm having trouble visualizing it in my head. I can build pretty much anything I can visualize, though.

Sounds interesting, though.