Low Feed Pressure:
If you see lower than normal feed pressure but you are making the correct amount of water for your system, there is no problem.
If contaminates have made their way into the Clark Pump it can get an internal leak. When an internal leak occurs the Clark Pump’s recovery percentage drops, feed pressure drops and product water production drop. So, a drop in pressure and drop in product can be a Clark Pump problem. To be sure that the drop in product flow is not from low feed flow in general (worn feed pump, low voltage, general flow restriction) it is suggested to hand calculate your Clark Pump’s recovery percentage. This process is called a flow test. Refer back to your owner's manual for instructions on a flow test or visit the below link.
Production Troubleshooting/Flow Test Detailed Write-Up
Pressures below nominal can be due to worn Feed pumps, Low voltage, suction side flow restriction, poor membrane condition or a Clark pump problem.