I'm still struggling accepting this ID. Call me loopy, I know. Jared, the markings you posted of the Atlantic carpet have well organized spots, and no red markings on the bottom of the foot. The red markings on the OP's pic shows a different marking pattern, and show up on the bottom of the foot. From what I understand, Mertens have disorganized red markings all the way to the foot, and under the foot. You're all probably right, it's just me struggling....
OP, do you have any pictures of this anemone when it opens up under lights?