No I don't think you have to cycle a tank that small and I can say for sure just a little filter will do. I don't think you can keep any fish in there long term (probaly not even a good idea for short term) but ya can have a nice crab running around and a little coral. I think i am going to get a little tank like this cause they are cheap to start up and I need something that wont be a hassle when I move. Which will be soon.:happy:
Skimmer not needed but daily top-offs and weekly water changes.Try sexy shrimp or 1-2 small crabs and 2 snails.Pantyhose (knee-hi's) w/carbon in the filter instead of the sponge it comes with.Ric's & shrooms will do fine.Cool lil tanks but you can't slack.