1. You should keep the temperature in your aquarium constant. Constant change in the aquarium can be dangerous for the fish in your aquarium. Keep a quality heater and accurate thermometer to ensure that the water stays stable for the aquarium.
2. Goldfish require a PH level of around 7.5 to live comfortably. Use PH testing strips to ensure that the levels in your aquarium are just right.
3. Do not overfeed the fish in your aquarium. Keep your feeding times at scheduled intervals to avoid overfeeding. If you are just starting your feeding routine, start out small and increase the amounts you put in on how much your fish eat.