I have a customer that has an old DE filter. They want to replace and dont have any preference of which filter. I have a sta rite cartridge filter in stock that they want me to put in because ill give it to them cheaper. Anyway The old filter had a brass push pull backwash valve and copper piping going in to the heater. Can i just slide the new filter into the backwash valve and just not use it? or will this cause a problem?