New drip system question

[Twilly]

I just setup my first drip system to grow some Potatoes and Carrots. I used sand and vermiculite as a medium, and I placed 2 - 3/4 in pvc pipes with holes in them in the bottom covered in a cloth sock to allow excess water to drain back to the res. I have the drippers connected to my NFT system pump which is on all the time, and I used 8 - 1/2 gal per hour drippers from Lowes ( But these are designed for full water pressure, so I'm sure they are not dripping 1/2 gal per hr )
My question is, am I going to drown the plants? What type of pump cycle do you use?