We just opened our pool today. The filter seems to be in fine working condition. We were 15 minutes into vacuuming the bottom to waste without a problem when the pressure severely decreased. We cleaned the filter and turned it back on. For about 30 seconds, it worked great and then after that pressure was lost again. We attempted to backwash/rinse/change the settings and again found decreased pressure. Any help you can give on how to remedy this would be appreciated. Thanks!
This could be as simple as the need to replace the O ring in filter head or the one in the pump filter basket. Either could cause the type of failure you are reporting if it is damaged. Additionally, a small leak or crack in the lines or fittings may cause this type of issue.