I just opened and cleaned the Pentair FNS 60 DE filter. I removed and reinstalled the bottom drain plug to clean the filter. I put some teflon tape on the plug threads. Reassembled the filter. Loaded the new DE. Now I found out I have a drip out of the bottom plug.I tried tightening but it is still dripping. Any suggestions? If I drain the water to remove the plug and put dope on it, do I have to backwash and replace the DE again?