How to change cartridge filter

• 1). Turn off the power to pool pump.
  
  
• 2). Close all valves going to the pool. This will prevent the pump from losing prime.
  
  
• 3). Open the air pressure release valve located at top of the pool cartridge. This will relieve suction on the cartridge.
  
  
• 4). Unscrew the locking ring on cartridge. Most units have a locking mechanism that must be disengaged, usually by pressing on the lock while simultaneously turning the lock ring counterclockwise.
  
  
• 5). Remove the lock ring and top of cartridge. Grasp the filter firmly by sides and pull upwards while using a gentle side-to-side twisting motion. If the filter has a top, there will be some suction. If the filter is open on both ends it should come right out.
  
  
• 6). Install the new filter. If this is the first time you have replaced the filter, you can locate the part number on the top ring of the filter. The part number usually incorporates the square footage of the filter, for example Hayward 120.
  
  
• 7). Push firmly down on the filter to ensure it is seated properly. Apply a small amount of petroleum jelly to the o-ring located either on the outside of the cartridge base or the inner rim of the cartridge top.
  
  
• 8). Seat the top firmly onto cartridge base, making sure it is evenly seated all the way around. Re-install the lock ring and tighten until lock mechanism engages.
  
  
• 9). Close the air pressure relief valve and open all pool valves. Restore power and activate the pump, checking for leaks as the water begins to circulate.