I would use spring water, from a grocery store or a spring, if there is one nearby. Test your PH and Nitrogen levels at least once a week. you will probably need a filter or some plant or change water a lot or less fish.
...a earth worm? He didn't like flakes so I gave him an earth worm. I saw him eat a little, should I just leave him with the worm to eat for later? he is about 3 inches. Should I take him back to the lake and set him free? I like him and think he is neat, but he seems sad, and wants to be...