Peppermint shrimp, great Aiptasia eater

I added one Peppermint shrimp to this set-up, just to test it's capability in eradicating Aiptasia Anemones. I had two new (and 2 old) Aiptasias growing on the rock. I wasn't sure why this sort of anemone started growing in my tank, since the 2 old Aiptasias weren't thriving at all. Something did change in this Nano-reef lately and I wasn't sure what.
I did some water testing and all except KH (6.3KH) was good. Since my Ca levels are Hi, at 450ppm, it is impossible to raise the KH, so I am stuck for a while, until I lower my Calcium levels.
In any way, I got this lovely looking shrimp to see for my self how effective it is in eating Aiptasias. 24 hours after introducing it to the set-up, the Aiptasias were gone !!! Is it possible, that this shrimp alone eradicated all 4 Aiptasias alone? I bet it did, since they were gone.
I have read many stories on the net about the Peppermint shrimp. Many say it is good and many that it is bad at eating Aiptasias. Is it possible that people are talking about two different species of similar shrimps?? I am not sure, but I sure can state that this shrimp of mine is very effective in removing the Aiptasia Anemone. My Aiptasias were no longer than 4cm, so still very small. I am not sure would this shrimp be able to eat a big Aiptasia though.