A week ago we picked up 4 more fish at the LFS. 2 are Firefish and one Midas Blenny. We put them in our 55 gal QT observation tank that has some large pieces of rock but BB. The Midas is very active swimming all around the tank and backing into a rock hole when resting. But occasionally we saw it chasing and nipping at the Firefish. The final straw was when we saw it pin one down in a corner. For fear it would kill one or both I netted out the Midas and put it in the 180 DT. The DT is aquascaped with a lot more passages and hiding spaces plus sand. He still actively swims the whole tank but isn't bothering any of the others. It has a Lawnmower, Cardinal, Foxface, two Clowns and two Skunk Shrimp. I'm hoping that with more room and rockwork, he leaves the Firefish alone but what are the chances ?