Ok well for starters I'm only 13 years old. I know that its pretty easy for me to be doing something wrong but the problem is I just don't know what. Yes, yes I have done my research don't worry I don't use tap water I use the water from the dehumidifyer... If that's spelled right. Anyway I know my betta fish can live in it so I'm pretty sure my goldfish can. Oh wait I forgot to tell you what happens... Woops :P OK every time I get a goldfish they die the same night or in the morning right after school starts. I don't UNDERSTAND. They are living in one of thoes bubble gum machine tank things... I don't know if you've saw one before but they are maybe 25cm wide if that sounds about right and the same length tall.so if you are and expirienced fish owner please help me asap