HELP Fresh Water vs R/O water

[fishguy007]

Hello,

Just set up 1 90 Gallon. I used water from the tap and used prime on it. Then I added my live rocks. Now I am being told that ro water is the best.

So I went and bought some. I am using R/O water to top off the tank with evaporation.

Is this okay? or should the full tank have been filled with R/O water.

Thanks.