Hi I just got one of these. I set it to #3 so pretty low and connected it to my Skimmer. I also have a handheld ORP meter to check. Unfortunately either the Poseidon or the meter is defective but I have no idea which. Is the Poseidon silent?? Because it lights up but I cannot hear anything unless I put my ear right on it therevis a tiny buzz inside. If that's correct than likely my handheld is too crappy to monitor. Thanks !