so my favorite macro algae of all time is acetabularia. it is nearly impossible to keep in the aquarium. i was maintaining a small colony of it when my euchuema crashed causing me lose several species of macros including my acetabularia. well around the time of the eucheuma die off i had moved some snails from the macro tank into my frag tank. and sure enough a few weeks later i had acetabularia growing on my snails. i was gonna wait to see if it lasted in my frag tank but sure enough it continues to grow on my snails, not if i can get it on some rocks. i honestly would just love it if it would over run the whole tank.