New to reef keeping but I see dozens of posts about zero TDS but I am a biochemist by trade and I know that is almost impossible. What is the standard zero TDS in ppm? I have access to water that runs between 0.40 and 0.50 ppm TDS (tested on a calibrated TDS meter daily) and on a really good day might get to 0.35 and I doubt most people at home can get that low consistently.



