stone

Hello,  I was just wondering what methods you guys use to make any rocks you may find outside safe for aquarium use? I have read you can boil them or bake them but I just wanted more opinions :).    Thanks!

At the invitation of Shrimp Addict I have started my second thread. After a good 1st year of fish and shrimp keeping in an 80cm tank I went for one of these as that's all I have room and also frankly funds for, justifiable and otherwise. I planned design well in advance, but after advice in shop...