watch the video of it in action, it is so quiet and powerfull, to build it from new i recon from £60 to £80 the young lad works most days with it, and their are no problem, to controll the water flow, it is best with remote control or manuel switch,
their is audio, it is just because the pump is so quiet
http://www.youtube.com/watch?feature=player_embedded&v=C2jsDFBOvps