Ok ill type this again since a "data base error" lost my post.
To my understanding Lettuce Nudibranchs do not eat HA the eat bryopsis. If you want something that eats HA get a SeaHare or if your lucky enough to find one a Dwarf SeaHare. They can grow pretty quick and completly wipe out the HA in a matter of days. If it runs out of food make sure you got a buddy lined up to borrow it. If it dies it has the potental to nuke your tank. I have one workign full time in mine.
they shouldnt...My seahare is about 4-5" and doesnt knock anything around. No where near as bad as a urchin or even hermit crabs. Like I mentioned though a lettuce will not eat HA. (or atleast the vast majority of know instances it wont)
i have the lettuce nudi's in my frag tank as I've got a raging hair algae problem. there's 3 in a 30 breeder and they're eating it, just not fast enough. I just threw in hermit crabs and a rabbit fish...and ordered a new light bulb. hopefully I'll be able to get rid of that stuff in there as its HORRIBLE!
but again. My lettuce nudi's DO eat hair algae...just not fast enough!
thats good news i dont have much just mainly on the frags im hoping they can eat the hair algae on my zoas frags without damaging the zoas. would you happen to know if there is a limit of lettuce nudi's you can have in about a 45-50g tank?