Well, I've been getting enough questions and comments that TCLynx suggested I start a discussion so here it goes- I definitely want to hear about anyone elses attempts at vertical hydroponics, and I'm more than happy to share any details of my system that folks are interested in.
TC- Where do you find that media? I get my media from a large plastics company- the problem is, they only sell it in massive quantities (i.e. minimum orders of thousands of square feet, min. $5,000.00 an order or so). I got my intial stuff as a researcher, so they were willing to work with me. I'm currently using the stuff for my towers, and I'm trying to start a business selling towers (eventually) so I can make big orders. If you want a chunk of it, i could send it to you, or if you were interested in more, i'd split an order with you however you want. i also have lots of scraps- it's really cool stuff and it would be great to see more folks playing with it- i'd send you some scraps if you want. email me if you're interested- i'll send you thier contact information too if you want- but i've found they're really unwilling to work with folks interested in small quantities (they're wholesale).
Have you used if for any purposes other than your vertical growing towers? If so, what did you try and how were the results compared to other media. I've played with it a lot over the past couple years, and it's neat stuff. there are some folks using similar material for floating islands. I've used it as filter material, and water diffusion material, but the towers seem to really be what it works best for.
Have you tried direct seeding into it or only with seedlings? What are your seed starting methods for the seedlings going into the towers. The material isn't suitable for direct seeding- it's too coarse and porous, and really doesn't "hold" water like most starting materials. I start my seedlings in peatmoss or rockwool and then transplant the seedling peat/rockwool and all. I've experimented with different starting techniques, and the tubes do best with a peat/perlite/verm. mix that just goes straight into the towers.
Hope that starts to answer your questions. I'll put up some pictures of how i transplant.
Some one over at BYAP mentioned possibly using the towers for a green roof modified NFT. Sounds kinda neat but the logistics of making the towers work for that might be a bit tricky.
I've got some seeds started in cotton with a rayon mop string wick in the NFT pipes and I intend to see how the plants do from that into the towers.