Well, I don't necessarily agree with that statement...I have had some seedlings in perlite with the roots completely submerged under water: the plants seem to do fine as long as the roots get enough oxygen without much contact with light. The way I look at it, a mature plant is going to have its roots dangling in the water, and as long as there are no signs of overwatering, you are doing fine. I feel it is completely easy to start in perlite if you have never attempted a hydroponic grow before. You can grow in a quart sized paint bucket, just drill some holes in it (it may be ghetto, but it is the same basic principle as a netpot). Once the seedlings mature to the point where they need nutrients, throw them into your dwc system and watch em grow.