Hydor Koralias and nudibranchs, do they mix?
 

So I want to place a Hydor Koralia 1200gph in my tank, I have 6xsea hares of about 2 inches, and one big one of about 4 inches and fat and big.

Will they be atracted to the koralia?, I mean I've heard that it is the heat from the powerhead what really atracts them, but in this case the Hydor Korallia has no heat apparently.

I haven't had any problems, however I have only one sea hare

I have 2 Lettuce Nudibranches and a Koralia 3. No problems. (now that I typed this I'm sure they will both get minced)

They crawl all over your tank. Sooner or later, they will get sucked into the pump.