Yes, listen to the experts (of which I'm not one) and GET RID OF IT NOW. I've had it for over a year. At first I didn't know what it was. Tried to explain it to LFS and they had no idea what I was talking about. Then it started choking coral so I had the brilliant plan to cut it out with a knife. Within a few days of the aptasia massacre the tank had exploded with aptasia everywhere - growing on rock, sand, glass, coral, even on the shell of a moving crab.
I bought 20 peppermint shrimp who didn't touch it. Bought a copper banded butterfly who died after 4 days from being hassled by the other fish. The second copper band butterfly (somewhat bigger) is now in the tank for a week and hopefully will eat the remnants.
I was ready to get rid of the tank, but last week found out about Joe's Juice, which has restored my hope and love for this hobby. After a couple of treatments, 95%+ is gone, and I'm now down to the hard to reach ones. I'm doing frequent water changes as I used a lot of Joe's Juice, since I had hundreds of these things.
Can't say enough about Joe's Juice. Get it while it's cheap. If I were Joe, I'd triple the price. It kills the small ones instantly. The large ones might take a couple of treatments. It spots up the glass like white paint, but a scraper get it off. In the very heavy treatment areas it left a white film on the rocks, but I'm hoping that comes off with a turkey baster in the next water change.
The aptasia nightmare cost me about 1/3 to 1/2 of my coral, which I'll start restoring as soon as 100% is gone. Thanks to Joe's Juice.