I've never had a problem with it. I'm always careful to use as little as possible though. I use so little, that I doubt it impacts anything.

I have had success with hot vinegar too - doesn't hurt anything else.

How did the berghia nudibranches work out for you and what did it end up costing you to have them shipped up ?

-captainhemo

The berghia were brilliant. They bred in the tank and kept going until all the aiptasia were utterly destroyed; took 3-4 months. At that point they were starting to starve, so I caught as many as possible and brought them in to my LFS for store credit. I hope Colby has success breeding and selling them, I think it would be awesome for berghia to be available at the retail level.
Total cost... hmmm. I think it was around $100. But I got $40 of that back, and I probably could have recouped more expenses if I had been more diligent about catching and selling them. If you have a small tank, it probably wouldn't be worth it; the shipping minimum is 8 when they ship outside the states. But for a larger tank (I have a 90g system), I felt it was well worth the money.