[Bill Little]

This whole topic can get very contentious or confusing very quickly. First of all you limit your discussions here to FW. SW adds a whole different set of parameters I have always been told that working in FW a conductivity meter is the way to go. In converting TDS readings to conductivity some sources suggest multiplying the TDS reading by .63. Other sources suggest using a factor of .50. I have always used the .50 factor and have not had any issues (the calculation can also be done in your head).