"safe" depends on what you have in the tank...and what you are willing to possibly loose like Inovator said, they are all predators.. I had a green terror as stated earlier and he was exactly that, but he was also about 8 inch across too(huge!) I have very small very docile fish, the most agressive thing is my false percs he got my clown goby... and one of my baby false percs, he actually ate my brittle star which was about as big around as half dollar but once again, he was big enough to do that...it was actually a hitchhiker. they are somewhat opportunistic feeders i actually used to feed him directly so he wouldnt terrorize my tank, as far as getting him out, i just netted him, he always came out when I fed so I dropped a small piece of shrimp in the front, open part of my tank and he came flying then i just swooped him up, good thing is they dont have eyes so netting him is easy
I;m so deep that if water tried to listen then the rivers would sink...knowledge is power, get ya weight up!