Goldfish death

Question
Hi Jaymie,
Fish Deeva had helped me with my fish in the past, but she is on vacation.  I am hoping you can help me.  My goldfish just died last night.  He had stopped swimming and eating (about 4-5 days).  His abdomen seemed a bit rounded, and began to turn grayish yesterday.  I assume it was fish bladder disorder. I have a 20 gallon tank with pump and filter.

Here are my questions: given that i am not sure it was fish bladder disorder, do I need to do anything to my tank before I acquire new fish, and if so what?  If I wait about two weeks to buy new fish, do I need to cycle the tank all over again?

Thanks in advance for your help.

Answer
Christine,

 What I have done in this situation is turn the heater up to 88 degrees, keep the filter running and add a little food to it everyday to keep the good bacteria. Leave it like this for 2 weeks and then put the heater back to its normal range before adding more fish. The rise in temp will help kill off anything that might be in it. You will not need to recycle the tank as long as you keep everything running. Also do water changes at the same time.