Help!!!! Red Sea G2+ 300 Diaphragm valve replacement

[ryrybeanie]

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?

 

[exnisstech]

Those valves are finicky. I have the older black valve on a 170 and the newer red one on my 300. As finicky as they can be I have never had one fail. Normally noise is caused by the valve needing adjusted or the water level is incorrect.
You can just turn the return pump off and let the water drain then you shouldn't get more than a few drops of water. I've disassembled mine for cleaning a few times and shutting off the return was all I did.

 

[MarineandReef Jaron]

These really should not need to be replaced but if you want you can replace the rubber diaphragm. These can get damaged if too many worms or other calcareous animals get caught in them.
https://www.marineandreef.com/ProductDetails.asp?ProductCode=RRS40370