re establishing goldfish tank

Question
I just had several goldfish die from various bacterial/parasitic diseases.  Soon, I am looking to buying new ones.  what should I do to the tank before acquiring new fish?  How do I get rid of what may be in there?  how long should I wait?

Answer
John,

The best way is to clean the whole tank out and start fresh. If that is not an option, you can add a heater and set it to 85 degrees and keep it going for 2 weeks. This will kill anything that is left in the tank. Make sure you keep the filter going and add fish food to keep the beneficial bacteria. After the 2 weeks, remove the heater and wait until the water has gone back to room temp before adding any goldfish. I hope this has helped.