Fish are dying! home fish aquarium?

First, you can't mix gold fish with tropical fish. Tropicals need a heater, goldfish don't. How many gallons is your tank? Goldfish are also very dirty,messy fish. Only one goldfish per ten gallons of water. STOP adding more fish! When you change the water use only distilled or filtered water. Do a partial water change once a week, about a quarter of the water.