Fishguy2727
Aquarium Advice Addict
- Joined
- Sep 24, 2010
- Messages
- 2,667
A water softener just exchanges one Ca or Mg for two sodium so the total dissolved solids actually goes up. There are probably other filters (carbon is usually used for chlorine). I thought the same thing about mine but even the "0" readings I got proved to be inaccurate. Eventually the tank was just a hair algae farm and it took a long time to get it back to where it needed to be. This was in a reef though. I use my tap for all my freshwater tanks without any alteration.