I am a first time pool owner and this forum has been invaluable. Most of my questions have been answered by searching this forum.
I looked up the instructions to clean the filter cartridges and noticed that the drain plug is located about 1/2" from the pump (see attachment). I do not see a way to open the drain plug (no room) unless I am missing something. The pressure is well within the norm (about 18psi currently) and since the pool is 4-5 years old I am assuming it has been cleaned before. Any suggestions would be greatly appreciated.