Ok, I already have a good filter, I was just checking if I should use it or not....looks like the answer is yes. Yes, I do know about Cycling as I used to keep fish when I was younger...I plan on just starting with one Axolotl and maybe getting another one later, I am not sure. Tank is about 55X30X20 (Lenth, Width, Height in cm), but I have other tanks of similar size/slightly bigger I could get out of the garage. Thanks for the help!