Help!!!! I need to replace the downflow valve on my Red Sea system. First how can I make sure no water comes out of the downflow so I can first take the valve apart? I am getting a gurgling sound out of the downflow and turning the valve to close does absolutely nothing. Second should I replace with another Red Sea diaphragm valve or should I start doing some plumbing work? Is there a way to replace the piping under there without water coming out all over the place?