George, I have done alot of research on these. they are good if your tank is really overran. what usually happens is that in the beginning they do great when the food is abundant. but as the aptasia gets less and less they have to travel further and eventually they will starve to death. they are very very sensetive to tank changes also. I just think in my opinion there are too many negatives to try this method. but that is just me talking. I would do a copperband before berghi's