Just live rock, a hang on back wisper 200gph filter and a power head. No overflow. I expected to find bones on the bottom. This tank had no sand. No pets. The only logical concludition is that everything feasted on a dead fish and the bones leaving nothing. The tank was established for a while, everyone was doing well. The angel fish ate normally just the night before and in the morning it was gone. I thought a rock might have fell over on it and the clean up crew worked overtime that night. But no bones?? I expected to find bones. What I found was a clean glass bottom. There was about 200 lbs of live rock, the odds of someone stealing it is slim. They would need to take out all the rock to catch the fish. I took everything out of the tank yesterday to upgrade to my new 150 gallon.
So now there is no rocks, no sand, no angel fish and no bones on the glass bottom. Strange.
As of now I can only think the shrimp and crabs ate the bones leaving no trace. Hoping someone else could explain.