I certainly believe that. However, when you first add water to a tank, you will have 0 ammonia, 0 nitrite, and 0 nitrate.
However, having a fish in there now, you will get ammonia from the waste (ammonia is toxic to fish) The ammonia will turn into nitrite (toxic to fish) and ultimately into nitrate (not toxic in lower levels)
Before adding fish, it is highly recommended to cycle your tank by adding a non-living ammonia source.
Considering you already have your fish, I would do water changes every day.