I'm very new to hydroponics, but if I can offer a suggestion? Can you post a picture of your situation? It would allow for some better understanding of what you are dealing with. I made a pvc superstructure to allow for support when my tomatos need it eventually. My setup is indoors though. Post a pic so we can help.

I assume you're growing tomatoes based on the size of the plant. Simply cut off all leaves after the first leaf cluster below the lowest fruit and coil the stem at the bottom.
You can also crush the stem at the tip of the plant to slow the plants growth and shorten the nodal spacing of the leaf clusters (which will also shorten the plant)
As for support, I normally use a string and tie a loose knot around the plant near the top.

I have been using old stockings that my wife discards which are really good and do not cut into the stem of tomato plants. I have been training my tomato plants up 2or 3 vertical ropes and as the plant grows I then tie with a portion of the stocking which I have been using for many years, they do not rot quickly and will last the entire growing season. I have also attached a photo of a product available on ebay which allows the plant to grow and be supported during its growth cycle may be of interest.

thanks for your input guys!

I decided just to buy one of those ultimate plant cages to try and then figure out if i wanted to buy more later.

And robert.1943 since you shared that with me, maybe you would be interested. When i was on the website is saw they also have ultimate plant clips as well. check out the link here: http://www.globalgardenfriends.com/product/ultimate-plant-clips/

Hi Guys,

Also very new to hydroponics. I'm interested in growing bell peppers in a NFT system using 4" pvc.

What are your thoughts? I've heard the roots can become clustered in the pipe and lose oxygen.

Also what would you advise as correct spacing between each plant?

Are you thinking sweet peppers, hot peppers, or bell peppers?
I can't speak to bells or hot, but I've grown sweet peppers in an NFT system made of vinyl downspout. They measure 2"x3". I'm not sure clustering in the pipe would cause them to lose oxygen but I did have to increase the slope of my troughs to keep the nutrient from backing up.(and spilling out the back of the trought) I spaced my plants at 8" on center with the rows approximately the same. I staggered the spacing though.
there are some pictures in This thread as well as some discussion on stunted growth I experienced and an issue with wind if memory serves me.
Actually I may have started them as EnF then transitioned to NFT. Hard to recall now.
Anyway, for sweet peppers, I don't think 4" pipes will cause clogging issues. Just make sure the roots come out of your net pots adequately before putting them in the system.

If you have worries about the size of the plants, it might be smart to grow one of the pepper varieties that is advertised as suitable for container growing. They are more compact. I put a link to some below from Burpee; there are many other container varieties as well.

Here is a link that might be useful: Burpee's container peppers