water evaporation, how much is normal?

Question
Hi there, I am just begining to set up my new tank, (60 gallon bow front)  I've been doing a "test run" with just freshwater and all my new equipment, nothing seems to be leaking but I seem to be loosing about 1/4 - 1/2 an inch of water every few days or so, its been running with just the filter for about a 2 weeks,I've been adding my hoses and stuff to make sure everything is os working order, my pumps and hoses are not leaking, or the quarium itself, is it normal to have that much evaporate? I want to make sure before I add my salt, (i've put my live rock order on hold till i'm sure its ok.  I know salt water tanks require much more monitoring than freshwater, and I have no problem doing daily checks, I just want to make sure its normall before I get started.  Thanks!!!

Answer
sounds about right. i add a half gallon a day to a twenty five. replenish whatever it uses daily with fresh, not salt, water. the salt content will keep increasing if you add salt mixed water. the salt remains constant and only the fresh water evaporates.