[SJS]

I am going to go with other - i have tried the boiling water - took care of them - for awhile - same one's grew back so I must not have gotten it into the base. Then I tried Kalk - same result. I have now taken out the piece of rock and spot treated it with muriatic acid. I will let you know the results.
I dont want to add a critter to eat a few (5) offending weeds.
I think the best defense to these things is inspecting every rock you put intot he tank. I know mine came from a mushroom rock. Had it in QT found both aptaisia and bubble coral. Got rid of it - so I thought - put it in the dt - both came back. Said rock is now back in QT...