Cucumber Newbie- Need advice

If you have an extra grow light or two if it grows too far out-of-bounds you should be okay - I would be most concerned about the roots getting over-crowded in a Harvest. A trellis behind the machine would help a LOT, mine is growing in a Farm XL and I've had to give it several lines of twine to hold onto on the front and back of the machine. I think a metal trellis would also be a good place to clip supplemental grow lights onto, if you end up needing them. Here's what mine looks like today:

And here is a not-so-great photo of the roots, but there are quite a lot of them:

I know a lot of people turn their plants while small to make a root ball instead of letting them spread out in the water like I do - I believe to make rinse and refills easier. A lot of people also trim their roots. I never bother with rinse and refills or root trimming, but I have either 5 or 3 gallon water reservoirs attached to all my machines that I let get sucked pretty low before refilling, which is probably what's saving me from nutrient lockout. I'm assuming that's why people do the r&r's anyways, aside from the AG instructions say to do it. I can't say I read the instructions terribly closely, other than assembly.

Also for cucumbers, I highly recommend getting a parthenocarpic variety, so you don't have to deal with gendered flowers and pollinating by hand. Mine is Mini Munch, which I love, but I'm sure there are others out there. And don't be alarmed as the plant grows and some of the leaves look like garbage, especially the ones lower down on the plant. They are pretty much continuously dying and regrowing, something I had to get used to in hydroponics but never noticed growing them outdoors. Probably because they naturally drop and get blown away by the wind outside, but inside just stay on the plant until you pinch them off. And get ready for TONS of cucumbers!! I've been happily snacking almost every day on a cucumber from my garden for the past month at least, probably longer. They come off in pretty good groups of 5-7, and this variety keeps well in the fridge for about a week, the longest I've ever kept one in there. Probably would have lasted longer if I'd needed it to.

Sorry it took me a little time to search these out, been wild around here - I go into detail about my water system here and here, including links to the materials I use!

It's really just 5 or 3 gallon bottles, with plastic water dispensers as the bottom reservoir. It's the same concept as the AG versions, just with bigger bottles and without the auto-siphon, but I've never been bothered with starting a siphon with my mouth, I just make sure I have a cup ready to spit the water back out, because I do add peroxide to my reservoirs as well as covering them with cloth to prevent algae buildup.