To me aptasia is like cleaning my sump, it’s gotta happen and it’s the least favorite thing about my tank.Every year or two they raise their ugly heads, usually it’s after my peppermint shrimp have been gone for awhile. If I let them get to big I’ll hit them with aptasia x then buy more peppermint shrimp. I don’t feed my tank every day so I’m thinking the shrimp are hungry and they scavenge more. Nudibranches to me are to expensive and more of a pain to acquire and wait to do their job. Aesthetically the shrimp are more pleasing to me