I have no experience with NFT, so I suggest you try this link: NFT Fancy Lettuce Systems

I think that most people doing such things probably use the rockwool starter blocks that can then sit in the net cups when transfered into the NFT system.

The plants need some support which NFT doesn't really provide without either a net pot or some sort of fitted hole around the plant.

I've been using a modified NFT/media system. I use an open trough with media (wood chips since they are free in my situation.) I like this method since the media holds some moisture and provides some buffer in case of pump failure or power outtage. It is also really simple and possible to even start the seeds directly in the trough if wicks are put in with the seeds.

I like the open top trough with media since they can be built from just about anything (mine are fence pickets nailed together and lined with plastic.) The guttering would work fine to make something like this but you need to make sure you have properly spaced supports to keep if from sagging and failing as the weight of nutrient collects.

I have also made a regular NFT system in a PVC fence post before (similar to downspouts). These types of systems have their cons since plant support requires extra $$ or tedium. Also, flow in the bottom of the trough is critical and upstream plants can get real big and sometimes block off the flow to plants further along the line.

Most of my lettuce growing experience has been in DWC since that is what I have indoors. Most of the year it is too hot outside to put lettuce into the outdoor hydro systems I have.

higgins11 looks like we are working on the same project drop me an email and we can trade ideas. I am looking at using vinyl rain gutter with a piece of vinyl siding cut to fit inside of the top with holes cut in it. Thinking of using swimming pool noodles cut to 2 inch long to fit in the holes starting my seeds in peat then putting in the hole in the pool noodle????? grew last year with a plastic lined box stirofoam sheet floating on top of water and nutrient mix used the tops of juice bottles with holes drilled in them for pots worked great just took up to much room in my small 10X16 greenhouse

Rock22r

everyone i've talked to said it works best if you can get your gutter down to 1-1.5 inches so when you start in 1.5x1.5x1.5 rockwool it just sits down in the tray and rest on the bottom

what Nutrient did you use.

I dont see your email

1 to 1.5 inch gutter seems small for a root base. I was looking at a plan for aeroponics and it uses 5'X5' fence post 6 feet long.Most of the NTF systems I have looked at the gutter is about that size. What Im trying to do is have my plant up off the bottom of the gutter and just the roots in the nutrient film. I use Dyna-Grow 7-9-5 My Tomatoes in my drip system are kicking. If you click on my page at the top of this post you will find a link to my email there