I'd love to hear about these. I joined that startup because I wanted to be a part of the alt-ag world, I left because I found out I was just part of the stoner world.
Google "Hydroponic lettuce farm Australia", a few big farms come up. They're not new, I think some have been running 30+ years.
Most of them look to be NFT using PVC drain pipes on a large scale.
Ah so DIY, I wasn't clear but that was what I meant by "small scale". I'll check out this stuff, thanks.