[jpdutton]

I don't know what you mean by back flushing???

I hope you don't mean you are trying to push water through it from the exit? If you did this you probably ruined your membrain.

What you want to to is flush the membrain. flushing works by bypassing the flow restrictor on your RO system and allowing a fast high speed flow of water to pass over the membrane surface and clean off any debris or scale that would otherwise clogg and shorten the life span of your RO membrane.