The B & A (before and after) total dissolved solids meter provides a real time display showing the TDS before and after the membrane. For example, if the before TDS is 100 ppm and the after TDS is only 5 ppm, your membrane is rejecting 95% of the incoming solids. If the rejection rate drops to 80%, a red light will flash to warn you that your membrane is compromised. You will be amazed at the poor water quality normally found in the Great Britain
