Converting to replaceable R.O. membrane

[mikem]

I have a Purwater PW-RO4L 5-stage R.O. system. It appears to be the same as the Aqua Pure with the same model number. It has a sealed R.O. membrane and I'd like to convert it to use a replaceable cartridge-type membrane.

Is there any reason I shouldn't replace the sealed membrane with a housing that can be opened and replaceable membrane cartridge? Any tips on doing that?