I just finished cleaning my Starite System 3 Cartridge Filters for the first time on my own. I put everything back together and used magic lube on the O-ring and primed and started to run the pump. The air pockets usually work themselves out within 5 minutes and the system runs normally. The PSI on my pressure gauge goes up to 25PSI when the pool pump sounds normal and then after 20 seconds the pool pumps starts making a funny noise like there is air in the system and the PSI drops to 15PSI and then 20 seconds later it goes back to normal. I tried to bleed the system by opening the pressure valve on top of the filter. I stopped the pump and re primed the system. Maybe I didn't put the cartridges back on properly or the O-ring may not be sealed and air is constantly getting in to the system. Should I open the filter and re lube the O-ring and put it back together again. Any advice or solutions would be appreciated.