To paraphrase GaryP - "The solution to pollution is dilution"
It is the size of your tank - toxins, ammonia, etc. spiked VERY fast after the death. Do a few 50% water changes and give it a few weeks to re-stabalize. If you run a skimmer, try to crank it up for a "wetter" skim, and change out charcoal once a week for a few weeks.
Careful on the large water changes to not drastically change temp, SG, or PH!
