Unlike some people on this board I don't claim to know everything. Therefore I won't give advice. From my experience it all depends where you are. Where I live in Calgary, I have had a great deal of success with my tap water. I don't believe for one minute that chemicals get added willy nilly. However, I will say that when I lived in Vancouver many years ago, I had little success with tap water. But then we used Gro-Lux lights because they looked cool. No wonder we fought Cyano all the time. So I say use tap water with caution. Check with people close to you to see if they have success before you do.
