Water Maker Safe TDS Levels

Question: What is the safe Water Maker TDS Levels for drinking water?
Answer: 500ppm (parts per million)
Now for some details: First, TDS stands for Total Dissolved Solids and when dealing with sea water RO, the TDS level is mainly composed of sodium and chloride ions.  A new RO membrane should start producing 100-150PPM water and then slowly climb until it reaches 500ppm and it’s time for a new membrane.  While out cruising I would constantly meet cruisers that didn’t have a TDS meter to check their water and were relying on how it tastes.  After their plants started dying and their cat wouldn’t drink the water, one of our friends bought a TDS meter and found out that they were drinking 1500 ppm water….yikes.  Don’t rely on the taste test becuase the TDS can start hurting your kidneys before you can “taste” the salt and at $25 for a good TDS meter, it’s a must have on a cruising boat.