[GpsFrontier]

Will deep water culture work better for things like potatoes and beets?

Again, trial and error. I have never seen anyone growing those crops in a water culture system, so I can't tell you how they did. I don't know about beats but potatoes plants can get quite large. Two problems with that are, first when the plant gets big it gets harder and harder to lift it off the bucket without damaging it. Then the plant suffers because it's to much work/trouble to take care of it. Second large plants suck up a lot of water. Unless you use a large 20 gallon bucket or so, you may be needing to add water as much as twice a day if you use less than a ten gallon bucket.

I don't have drawings of it made yet, but my plan to grow those is fairly simple. It's actually an aeroponic type system. Essentially building a waterproof cabinet where the root mass hangs down in and grows, the foliage grows up a trellis above the cabinet. I'll have misters placed all around the top of the cabinet (to rain water all over the roots), and baskets in the top for the plants to sit in. One side of the cabinet opens up when I want to harvest. I simply cut off a potato (or whatever) from the roots of the live plant and close it up again.

will having a short run system that uses several short tubes instead of a couple longer ones help prevent water buildup?

Water buildup is due to blockage, not the length. Blockage is mostly due to large root mass, and spacing the plants to close too accommodate the growing root mass (creating blockage). If the tube isn't to small for the roots, and the plants are spaced far enough apart in the first place, you don't need to worry about blockage. Another reason is too shallow of a drop from the feed side to the drain side, but that's easy to change by raising the feed side or dropping the drain side.

I'd also be interesting in your idea on quickly germinating and moving green onions, if you are comfortable sharing it.

I don't mind sharing any ideas, I just want to help as many other hydroponic gardeners I can. And I hope they would do the same. The system I built to grow green onions and radishes (I posted the link to) worked nicely. However I noticed a problem when I wanted to harvest the green onions especially. They were so closed together that all the roots were intertwined. That caused a problem because I would need to damage roots of some onion plants to harvest others. I came up with a design that solves that problem, while still allowing the close compact spacing. I tried it out last spring/summer, and though it was still just a proof of concept model, it functioned well. My problem was the germination rate. Not all the seeds sprouted (only about 50%), and I'm still not quite sure if that was due to growing media mix, moisture levels, seed depth, or simply the natural germination rate of green onion seeds.

But if I start the seeds in small plug and cells in a propagation area first I can make sure every cell in the hydroponic system has a growing plant in it, so no space is wasted. I just haven't decided on the best growing media to use for the small starter plugs yet. Polly foam is a good option, but has some issues. Coco fibor is a good option as well, but may be a bit more labor intensive to transplant on a large scale. But if I make my own starter plug trays, I may be able to make using coco fiber easier. Either way I need to create a flood tray for it so the sprouts can be watered on regular cycles. There are a few other options I'm considering as well, however they need to be just as cost effective.

Your corn setup sounds very interesting as well, would you just be starting seedlings in rock wool?

I don't really like rockwool. It tends to become waterlogged to easily, and that leads to things like stem rot, and root rot. That's why I like the coco fiber. Coco fiber still holds good moisture, but also lots more air and oxygen as well. For the corn, I wouldn't want to use small baskets on a large scale because they would be a pain in the butt to clean them all to reuse them. I would probably find a way to make my own plugs, or use cheap disposable plastic cups with coco fiber in it to start them in. The roots will tear apart the plastic cups as they get bigger, but who cares they will be thrown away anyway.