playing with fire?

[mpishi]

i had a bad aptasia outbreak a while ago (six or so months) that was well handled by peppermint shrimp
but
there was (is) one bad boy the shrimp didn't touch - at the time he was about an inch across

now he is close to triple that and the sole aptasia in the tank

am i asking for trouble letting him be - the 3 peppermints are still resident but make no effort to go after this monster

about a month ago there was one small aptasia on the other side of the tank but it has since vanished

on the same topic - how do these guys propagate in the wild (the aptasia not the shrimp)?

tia