I have built a small indoor NFT system, using 4" black PVC (ABS) I cut 31/2 " holes, at about 16" spacing. Since I am growing in front of a large bay window, I used 22 1/2 degree elbos to fit the windows, I have a 3 % drop, or 3 1/2 in. in ten ft.

I started the seeds, tomatoe, asian cucumber & bell pepper in 1 1/2 rockwool cubes, then transplanted the cube with seedling into a 3" cube in the pipe. All are growing well, except, the roots seem to be plugging the pipe, causing overflow. I have reduced the flow, as much as I feel I dare, but still have drips, near the center of the pipe. I am feeding each 10 ft pipe from one end, through a 1/4" hose. Any one have an easy fix ?