best way to set up the drain
 

I just built my first setup and there are a hundred ways it can be improved, but my lettuce is growing and it's green so I'm thrilled. I'm using 4" round pvc, but I haven't figured out a good way to drain it, and be able to adjust the level of water. Any thought?

http://www.hydroponicsonline.com/for....html#post2850

I saw the pictures of the setup in the other post and it looks very good. I also want to use the 4in pvc pipe for a hydro system. Did you use the pipe with pre cut holes in it or did you cut them yourself? The baskets look to fit nice and snug.

When I first saw the pictures I was wondering which was the fill line and which was the overflow line. By your question I am assuming that the pvc (bottom) one is the drain and the red (top) flexible line is the fill line. I am no expert but I think you will find, if you reverse these and make the top the overflow and set it at the height that you want then make the lower one the fill line it will work just fine. When the pump shuts off the nutrient solution should siphon back through the pump into the holding tank draining the growing chamber (4in pvc pipe).

I used a 2 3/4" hole saw. Just a tip if you do this, put the drill in reverse otherwise the teeth dig in too fast and it doesn't drill.

The red line in the in and the white pvc is the reverse. From what I have learned is that you want to be able to control the height of the liquid so that once you have roots hanging from the bottom of the basket, only the roots are in the liquid. So before that, you want to be able to raise the liquid level. I manually made sure that my seedling stayed moist until they grew roots out of the bottom.

I think next time I will try using pvc fence post since it is square and should be easier to mount a drain in.

Square pvc is probably easier to cut the holes in too. I would just want to make sure that they are black on the inside like the large round tubes are so that it is light proof to cut down on algae growth. Also I would want to make sure that they were wide enough to allow for the root growth. Thanks for the tip...

I have been adjusting the water height on both my peppers and strawberry's and have found they like it best when the water level is about 1 to 1 1/2 inches below the top of the growing medium on the strawberry's and about 2 inches below the top of the growing medium for the peppers. Any higher and I see signs of stem rot, any lower and the roots need to migrate to find water. Especially in the case of my strawberry's that are in the 3 inch baskets like your lettuce, if the water level is to low the growing medium wont be able to fully saturate with water and nutrients and the plants would wilt and start to dry out. Basically you would want to saturate the roots and growing medium but without soaking the stem's of the plant. Any plant's root system will try to migrate toward water but that just causes stress to the plant. They can grow faster and healthier if they don't need to work to get the water and nutrients they need.

Interesting. I thought I had read that the water should not touch the growing medium. My water level is about 1/2 inch below the bottom of the basket.

I just have to say, this info. is sooooo helpful.