Im currently cycling a 65 gallon tank with ro water that i got from a friend. Ive tested my houses water supply and my city water was 286 TDS, but also have a well that i use to water my garden and stuff and that came up as 15 TDS. I can easily hook up my well to a slop sink in my basement. SO my question is when Invest in a RO/DI unit should I hook it up to my city water or well water? Also if I should do well water would i not need as many stages since the input would only be 15 TDS?