water cirulation system

[StirCrazy]

I was thinking of making a network of pcv piping on the bottom of the tank then covering it with the sand.. from this I would have risers every so often that would direct the return water from my sump to the tank in different area's to create a good cirulation in the tank. my thinking hear is I wouldent have to use power heads.. has anyone done this and if so do you have any tips or hints? hell any coments even if ya havent done this but see some things I might have to overcome will be helpfull.

Steve

Oh ya I almost forgot I am lookingat doing this in a drilled standard 50 gal tank 36" x 18" x 18"