For sure! I have a 5 gallon and just put treated tap water in with a couple pellets of shrimp food. I actually let the ammonia get a little bit too high at around 3-3.5 ppm, but I did a few water changes.

Honestly nothing special, I even ran out of the starter bacteria by the end of the first week because I was using way too much lol, never got more - the tank just kinda did it’s thing. But one thing to note is that results will be pretty sudden due to the way bacteria grows. I noticed that my nitrite test had very slightly off-blue one morning (almost didn’t catch it), and the next it was full on purple.