Water quality help.

[kien]

There are a few reefers who use tap water just fine. Ultimately I think it comes down to a personal choice.

I like to use RO because I like the idea of adding water to my tank that has a zero TDS. This way I sort of know exactly (ish) what I'm putting into my tank. With straight tap water (in calgary and other cities) there's quite a bit of stuff (dissolved solids) in the water so you don't know what you're putting into the tank. However, this isn't necessarily a problem or a bad thing since there are quite a few reefers who use tap water without any problems.