A lot of people do. The only thing you need to be aware of is that tap water usually contains a level of phosphate that may cause some nasty algea outbreak in the future.
Originally Posted by ReefForBrains http:///forum/post/2529673
Save yourself the headache and use RO from day 1.. JMO
+1.
My first tank I used tap for the original fillup and like 2 weeks afterwards, before switching to RO. The tank wasn't 'right' for several months afterwards.
There's always going to be 'stuff' in your tap that you don't want in your tank.
I used treated tap water in S. Carolina for 5 years and didn't have a bad algae issue, I just started a new tank here in Arizona, and I am ready to get a RO this week....BAD ALGAE ISSUE, seems some water is better than others.
you can do a water test. The test is for tds ( total disolved solid) you want this to be as close to 0 as possible. I live in the Bronx. Our water is great but still use conditioner and I'm getting an ro/di. Or you can use distiled water
if you would by some chance have Detroit city water as i do it is some of the cleanest water in the states (there was a big thing a few years ago because someone was gonna bottle it out of the tap)
this is just what i have heard and read.