Tube anemones are generally filter feeders that require regular feedings of live or frozen small foods, and an emphasis should be placed on small feedings made as frequently as time will allow. Minimally, feeding several times per week with some krill or shrimp pellets seems to suffice. These animals live with their tubes buried deeply in fine sands and muds. The vast majority of these species are nocturnal, so you won’t normally see them all in their glory during the day.
They are not actually anemones they are cerianthids, but they were labled long ago and it stuck.
The one you have looks like a real beauty. Kinda like this.