Not sure if this is the right place for this but Ill post it here anyways. I have just changed my pre filter cartridges and noticed that my RO membrane housing was up side down
This caused an air pocket to be trapped inside the housing so the membrane was never submerged in the water. The problem is now rectified with all the outlet tubes facing up allowing the air to escape. Its been this way for about a year, I wonder if my membrane is now ruined.