I have no idea what happened. Two days ago I saw both loaches together, but yesterday I could not find it any where, I looked on the floor all round the tank, under the couch, tables, book shelves, and nothing not one fish. Today I ripped the hole tank apart looking for this fish but came up empty handed. The fish are way to big to be sucked up by anything or eaten by anyone, they were the biggest in the tank.
I do have decorative shells in the tank so I had to check the shells and guess what? I found it inside a shell so far inside the shell that it made the 3" loach disappear. The loach is dead. If you use shells watch out they could be dealth traps.