Originally Posted By: andedammen
Yes it's normal/natural H2S is produced in the decomposing prosess.
Standing water in well/tank/pit/pond............. can hold big amounts off most gasses.
Then when you stir it they are released, to air.


It is normally advised to start off an aeration system in an old pond slowly. Start with 1 hr. and add an hr. each day to slowly release the noxious gas. This could and will cause a fish kill.