Ummm...yeah, so I changed my mind.
After the trigger decimated any kind of invert life in the tank the hair algae just exploded! Although it is a neat effect as it waves in the current (
) I think I would rather
see my rockwork. So the trigger was returned and I'm rebuilding my clean-up crew. I'm sticking with the damsels until they force me to get rid of them also. The purple tang is now happy to be the undisputed #1 in the tank.
Glad I tried the experiment, but I found that without the natural janitors a predator tank was more work and less pleasure than a reef. Maybe I'll try a blue-throat trigger in the future. For now, I just want to get the tank clean!