Opinion on a hydrogen sulfide smell
I have a ceramic log that has a faint smell of rotten eggs every time I take it out of the tank to scrub it down. I do this every week with my regular water changes. I am assuming it is hydrogen sulfide, but why would it be associated with this one piece of tank decor? I have had no problems with the tank or its inhabitants, but it does concern me. Please let me know your thoughts.
I should add that there is nothing that I can see that has died or is decaying in the log. Thanks in advance for your thoughts on this.