Rizik..
I tried the gutter for nft, but found it to be a little too flexible..I now use pvc fence post and it is great..just cut the planting holes where u need them..no covering and they are rigid enough to be supported easily.
corky

Corky,
What do you use to make the holes in PVC pipe? I want to make 3" holes in the 5" PVC pipe and not sure where I can find the right tool?
Padma.

Corky- do you have any problems with algae? I would think that if you let light through the hole, algae could grow using the light and the nutrients, is that incorrect?

For: inguvap
To cut a 3" hole in the PVC, use and electric drill with a hole saw. These are available in most hardware shops. To prevent damage to the pipe, practice first on some PVC scrap.

I was looking around and I noticed some people using PVC pipe. What would be the disadvantages of using pipe (as opposed a trough with a flat bottom)? Would I just need to make the nutrient film deeper?

Why donÂt you cut an X in the plastic, put your cube through, & then cover it back up again? You may still get algae, but lettuce is a short term crop, so you will probably be ready for the next crop by the time algae sets in. Algae is going to be more of a problem when it gets warmer.

Rizik..Pvc pipe vs flat bottom trough..
Remember when growing nft u want a THIN film of nutrients flowing, its like pouring a little water on your kitchen counter top, u don't want it any deeper than that. Thats why it is important to have a flat bottom to achive this. Using pvc pipe one has to flow too deep to get enough width for the plant roots.
Cut the smallest size hole needed for the plant roots to fit thru..can't imagine why anyone would need a 3" hole..
U may have a little algae growing..but algae don't eat much.
corky

What happens when the water is too deep (ie. not a thin film)? IE. what is wrong with using a curved trough and filling it about halfway? I know that's not what NFT is about, but if it gets the nutrients to the roots, what's the problem? What does NFT allow that using deeper nutrient solution does not?
And about the algae- when it dies, bacteria and other decomposers may come in to eat the algae, and in the process mess up my plant. However, I've been reading around and it seems that I may be able to simply scrape the algae off.

rizik..

Running deep water may not have any effect, except for root rot..In my NFT I try and guard against water "ponding". Thus a film..not deep..but I have a hydro friend that uses pvc..and fills his pipe halfway with pea gravel..not nft but it seems to work.

As for algae, I don't worry bout it..only problem for me is that it may cause clogging of my feeder tubes..

I mainly raise heirloom tomatoes and peppers..and not a quick crop like lettuce..so the deep water and algae shoudn't bother u at all.
corky

Hi Rizik,
If you have a nutrient film that is too deep, it is not exactly a film, but it will work. Commercial hydroponic lettuce growers in Australia use nutrient solution flowing down a trough, but their pumps need to run almost continuously.
I have been growing vegetables for the kitchen table for more than 30 years, and I use coarse sand. Sand works the same way as pea gravel, in the article above. I grow in 150 mm (6 inch) plastic stormwater pipe with the top partly cut out. This gives me flexibility to vary plant spacings at will. It is a flood-and-drain system and I do get algae, but have some control over this by how high the coarse sand medium is allowed to flood.

Please have a look at my web site from Australia. It will show you how to make a simple system, make your own nutrient solutions from scratch, how to adjust the formulation and also includes Hints for Success, an FAQ section that is worth reading, and a few links to other hydroponic sites (none of which have discovered sand).
If you get stuck, the site also has my email address.
Please feel free to use it.

Jimr007
Australia.

Here is a link that might be useful: Simple Sand Hydroponics

You might want to investigate Deep Flow technique versus NFT, and see which method you want. If you want a greater fluid depth, you might need to add another air pump or one with a greater aerating capacity. The nice thing about a guttering system is you can clean algae out, but with an enclosed pipe, it will be more difficult.
I have had the same problem with NFT as wampuscat described  ponding & bacterial growth. It is a good idea to test your system as you design it to prevent this. Also - if you are in a high heat zone & have pump failure, your plants can fry very quickly.