Good question. I was young and dumb and thought one day I'm gona buy a tank and keep gold fish how hard could it be? Water ,stones a few plants and fish easy right? Wrong! I feel bad now looking back at the poor fish that got stuck with me. The tank went cloudy with in a week or two and when I found out why I was gutted then I started to loose some fish. So I gave remaining fish to a friends pond. Years later and lots of study I set up a tropical tank and cycled it and slowly built up. Now I have natives and a guppy tank soon to be two and still have some empty tanks. Yikes I think I'm hooked!