We recently bought a house with a pool (I think pool is about 4 years old). This is my first pool so forgive my ignorance and lack of the proper technical terms. I recently opened the Hayward cartridge filter container and cleaned out the filter using a hose. I put it back together just as it came apart, tightened the rings, etc, but now the pressure won't go back up to where it was (around 20-25 psi) and the pump never becomes fully pressurized in the visible area where the pump basket is. However, when the I run the spa filter, it seems to pressurize just fine. I've opened the air release value and while water squirts out it makes no appreciable difference in the pressure. Do I have air in the line or maybe debris or did I fail to do something when putting the cartridge back together??