smelly goldfish tank

Question
i have a large fish tank that did have 6 goldfish in. last night i noticed the tank smelled really strongly of rotten eggs after a partial water change i went to bed awaking this morning to find that 2 of the fish had died and the other 4 in very poor condition. i again changed the water cleaned the entire tank and stones now less than 24hrs after that the tank again is smelling awful please help as i love my fish and they are approx. 8 yrs old.

Answer
Hi Charlene,
  I would keep doing partial water changes for several days and I suspect that at the end of 3 or 4 days the problem will be cured.  

 P.S. Are you absolutely sure that there are no dead bodies in there, e.g., a dead snail or a dead catfish?

-- Ron
  rcoleman@cichlidresearch.com
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