did u stir up the current sand that was in the tank? you could have released gases that were under the sand or decor.
i know u said that u had sand in the tank...which would mean that u shouldnt have an UGF, but just to make sure...are u using an UGF?
there has to be a reason for the stench you said you could smell. did u find an old piece of uneaten that was hiding somewhere in the tank that u somehow stirred up when adding the new sand?
also, I think you meant to say that you had a 'close call'...not 'closed call'.
good thing u caught it right away otherwise there is a very chance that your piranha would have died.
i know u said that u had sand in the tank...which would mean that u shouldnt have an UGF, but just to make sure...are u using an UGF?
there has to be a reason for the stench you said you could smell. did u find an old piece of uneaten that was hiding somewhere in the tank that u somehow stirred up when adding the new sand?
also, I think you meant to say that you had a 'close call'...not 'closed call'.

good thing u caught it right away otherwise there is a very chance that your piranha would have died.