Chemistry concern on new reef

[Mark-Stover]

This is unfortunately what likely caused your losses... When left undisturbed, anaerobic bacteria can build up in your sand. These bacteria produce, among other substances, hydrogen sulfide gas. This is unfortunately a highly toxic gas, and can definitely kill your fish in this way.

In the future, it's best to only clean sections of the sand bed at a time, unless you habitually clean all of it.

This is the same reason that, when transferring tanks, you really should replace the sand bed (or rinse the heck out of it).

Very sorry for your losses.

I think you hit the nail on the head as to what happened. I didn’t know about the hydrogen sulfide. Based on the way they died, that makes perfect sense. Thank you for that info. Expensive, painful and deadly lesson learned the hard way. I’ve read multiple times that I will make mistakes in this hobby, but I didn’t expect it to be such a big one. Thanks again.