Cleaning a tank after fungus problem

Question
I have a fresh water tank that used to have fishes that die after suffer from some type of fungus; this is the 2nd time that I am trying to have fresh water fish and the fish dies shortly after I purchased it. I think it is something with the water; I have an Eclipse 3 tank; how can I clean the tank and get it ready for new fish and try to keep the fish a live longer?!

Answer
Raquel,
short answer is to clean the tank with a solution of bleach and water, rinse the tank, add your gravel and water a dechlorinator and you are good to go.
I usually use salt and water but if you are having reoccurring problems its time to bring out the big guns.
If you have additional questions, just ask.