How do you keep a 10 gallon gold fish tank clean?

I have a 10 gallon tank with pump that I set up about 8 days ago. I used a formula for the water as directed to treat it before putting any fish in. So far I have one red telescope goldfish in there but i want to add more. However, the water is kind of cloudy. Before I add more fish how do I keep the water... show more I have a 10 gallon tank with pump that I set up about 8 days ago. I used a formula for the water as directed to treat it before putting any fish in. So far I have one red telescope goldfish in there but i want to add more. However, the water is kind of cloudy. Before I add more fish how do I keep the water crystal clear? The guy at the pet store said to just wait and it will take care of itself, but nothing has changed. What do I do?
10 answers 10