I'm having trouble find a replacement drain plug for my 13 y/o 325 Series Hayward cartridge pressure vessel. I think my current one is on the verge of failure! Can someone direct me to a supplier in the San Antonio area or on line? Thanks!
If you can figure out the part number for the drain plug it is generally quite easy to order one over the Internet. If you still have the manual there should be a parts list in it. Or if you know the exact model number of the filter you can do a google search and often come up with sites that show the parts lists. When looking at parts lists on the Internet, take a little care to be sure they show the correct model. Generally if the parts diagram matches closely with what you have it will work.
I don't know the specifics of your filter housing, but on my cartridge filter housing I replaced the drain plug with a PVC ball valve. Sure makes draining the thing a whole lot easier, and in fact have added a bit more PVC to where I can hook up a drain hose and get the drainage away from my pool.