So in my 75gal mixed reef I have a major aptasia outbreak. I recently purchased 6 berghia nudibranch. They were at the biggest 1/4" long, smallest probably 1/8". After acclimation, I placed them in the tank all close to each other. They all were alive when places I watched them all scoot away 2 of them went straight to a small aptasia. They were still eating it the next morning (I think there were several small ones in the same spot). Since then I have not seen any of them cruising around. I did take a flash light about a hr or 2 after lights out a couple times and still didn't find any. I feel like I have noticed aptasia going away. I am just kinda wondering what other people's experience is with them. Do you see them often? Do they reproduce fast? Is it normal to not see them? Are they hardy? Do fish eat them? I do have a mandarin in the tank and a 6 line wrasse. My LFS said that 6 would be more than enough for a 75 and that ot should take 6mo to completely itradicate all the aptasia. I would love to hear all your experiences with these guys. Thanks