At first glance, it looks like a sebae, H. crispa. But, to know for sure a side pic showing the column would be helpful. Regardless of the species, all the host species prefer high water quality, as in undetectable nitrates, specific gravity 1.026ish, temp. 78-82, ph 8.2-8.3 preferably, good water circulation such as 20x tank volume per hour or higher, and reef quality lighting.
Moving around a lot means it's not happy about something. Likely causes of moving are nitrates, water circulation blowing directly on it from the pump, or insufficient light. I would start with a nitrate test followed by a ph test. Assuming it's a crispa, they prefer to plant their foot in a hole in the live rock with the column protected by the walls of the hole or cave where they attach. Make sure you have your pumps protected by plastic screen or foam to prevent the anemone from being sucked into a pump. That would likely spell disaster for the anemone and maybe everything else in the tank--anemones are loaded with toxic nematocysts.
Also, that large maroon could be irritating the anemone. In the wild, those two species never live together. In aquariums they sometimes do, and they are fine as long as the anemone is 3 times bigger than the fish (e.g., 2 inch clown, 6 inch diameter anemone).
