The standard guideline is to only relocate 1/2 of your ornaments at a time (cleaning etc.). My fish sometimes move more than that overnight, but my tank is designed to look like a natural habitat and has semi-strong current, I imagine in a river/stream that in any given spot there's quite a difference in branches/logs drifting by day to day.
I have to move driftwood just about every cleaning because I like to make sure my crayfish/crab and those darn snails (semi-infested :duh: ) aren't making too much of a mess under there.
I have to move driftwood just about every cleaning because I like to make sure my crayfish/crab and those darn snails (semi-infested :duh: ) aren't making too much of a mess under there.