fish tank advice

There is a such thing as good and bad bacteria for a fish tank. When you first set up a tank and get it running it is too clean for the fish. It is like us jumping into a pool with too many chemicals. What is that stuff that has a strong smell? Well anyways after about two or three weeks it's time to do a 10% water change. We did that, because our fish were dieing. Although, our fish aren't dieing anymore it's really cloudy. The water tested just fine. The person at the pet store said that the cloudiness will clear up 10 days after the water change. She said after the cloudiness goes away, it's a good time to get a few more fish. Also it's normal for most people to have their first few fish die. It's all just part of the process of starting a new tank. Her last bit of advice was to not over feed and to do water changed every three weeks. She said do just the water, then the next three weeks vacuum the gravel, just basically don't do all the maintenance all at once.