warmer than room temp. water

[tome]

hello, I'm trying to start up an active hydro system, and have a few questions for you. we have everything set up but i needed to know if i can continuously run water through the medium.Or do i need to put the pump on a set cycle. If i can run a continuous flow of water through the pipes is there a certain level the water should be at. I have an air stone running in the system. Do I need warmer than room temp. water? can the roots be completely submerged under the water in the pipe? thank you tommy two toke