make sure you supplement the sea hare with algae sheets or pass it on to someone else with a hair algae outbreak. Generally after the tank is out of hair, they slowly starve to death.
i had one and it did a lot of cleaning and i supplemented with nori sheets, but eventually it died so be careful because it can crawl into a space not easy reached.
@ stevec , yes mine to died. the worst thing I cant even find where it is right now. I just leave to my cuc.. but still really nice defend or quick fix for GHA..