I have a porc puffer, with 10 blue legs, 6 turbo's, 4 emrald crabs and 3 regular sized hermits. My puffer does not even look at them. My puffer is only about 3 inchs long though. He is in a 55 now but will be moving very very very soon. If you have a lot of LR they should be fine. I don't remember exactly how much rock I have but I am sure it's over 60lbs, so my snails and my hermits just blend in with everything around them. I was thinking of getting a SFE but decided to just wait until the 180 is done and the room around it is done also. "Just don't trust that sort of noise and dust with my tank".