The "puking" periodically is rather normal behavior as they use the same opening for feeding and for excreting. It is a bit horrifying the first time that you see it.
Don't be surprised if it appears to be doing fine and begins slowing getting smaller until one day it's gone. Anemones do not so well in captivity as a general rule without specialized lighting.
Watch it closely - I lost an entire 90 gallon to the death of an anemone fouling the water. I have since sworn of anemones.
Good luck - hope it works out for you.
You know you are a true fish-o-holic if you can field strip any powerhead on the market.