Tank Smells!!!!

[MarkoD]

so for a couple days now one of my fish just disappeared.... im assuming it died but i cant find it anywhere.

I've spent hours looking for it.

i was out all day and i get home and my whole basement smells. i dont even know what it smells like (felt really hot and humid and smelled like ocean or soemthing)

i run 2 large bags of carbon but it doesnt help.

any advice?