You can find Goldfish food at almost any pet shop. Make sure to purchase some when you buy your first fish. Feed only a small amount. Especially at first. Any uneaten food will sink to the bottom and rot. Keep this to a minimum. Watch your fish the first few times that you feed them. Feed only as much as they will eat in two to three minutes twice a day, or as recommended on the Goldfish food label. Be especially careful not to overfeed when the Goldfish tank is new. This will cause excess build up of toxic chemicals and can kill your fish quickly.
As the water in your fish tank cycles through the nitrogen cycle, you may notice that is becomes very cloudy. This is a normal process and should clear up in a few days. Do not add any new fish until the water is crystal clear again. Clear water will signify that the nitrogen cycle is working and that the toxic chemicals are being converted to good ones.
Remember that Goldfish will grow large and they need a big space. Don’t overcrowd the tank if you want to keep healthy fish. If you follow this little guideline, you will be sure to have a healthy goldfish aquarium.