look not only at your membrane size (e.g., 4040: 4" in diam and 40" long, nominal), but also at the test pressure, or the manufacturer's spec pressure. If your vendor doesn't tell you the factory spec pressure on the membrane you're looking at, consider a different vendor! If for instance it's 150 psi... consider getting a low energy (100 psi) membrane, or an extra low energy membrane (80 psi) of that same size. Continue to run it at your 150 psi as you always have, but you'll get much faster production. We stock 4040's spec'ed at 225, 150, 100, and 80 psi. Remember that the nameplate capacity of the membrane is also spec'ed assuming you have 77F water (almost no one ever does). Colder water = slower production - that can be addressed by going with a lower pressure membrane.
