Is my tank too small for my fish?

Question
I have four small goldfish and four rosy reds and they are in a small tank which has been set up since May of 2003 (my parents just bought the four goldfish a few days ago) I think a should probably get a larger tank, but I was wondering what is the smallest tank I could get and my fish still have enough room?
And how do I keep the tank cleaner longer, could you recommend something?

Answer
Hi Elisabeth;

I wouldn't keep them in anything smaller than a 20 gallon. They will outgrow this too eventually. Goldfish get up to 8 inches long and as you know, are pretty messy. They key to their tank staying clean is in not overfeeding. Make sure they eat all of their food within 5 minutes after you give it to them. (If their tank is too small it is impossible to keep it clean no matter what you try). Make 25% water changes every week to two weeks and vacuum the gravel at the same time. This is normal maintenance for any aquarium.

Followups welcome.

At Your Service;
Chris Robbins