At the price of it you can just try it and see. I do not think that it is at all recommended for sand sifters and burrowers though so I am not sure if it would cut the nems foot.Once again, I'm using by choice not by neccesity. I'll I want to know is if a carpet anemone will bury its foot in it.
Not sure I would want to do the "try it and see" method -- S. Haddonis, at least healthy ones, aren't super easy to come by, and wouldn't want to risk it. After watching how fast an S. Haddoni can fully retract into the sand (( about 2 seconds, at most )) I would be a bit nervous about it being cut.
I feel the same way Todd but the OP seems SET on using this sand. That is why I made sure to point out that it is NOT recommended for sifters and burrowers which this type of nem is.