The safest way to boil rocks is to place them in a large pot where they can be fully submerged. The water should be brought to a boil, and left on the lowest temperature that will maintain a steady boil. The pot should also be covered, and I recommend wearing fully safety gear while dealing with the rocks. In case of an explosion, you will want to have your hands, face and body protected
After the rock has been boiled for about 20-30 minutes, it can be removed from the pot. It should then be placed on paper towels to absorb any excess water, and allowed to cool for at least an hour. The boiling will have removed all of the bacteria and other life forms from the rock. Once it has been allowed to completely cool, it can be safely added to your Driftwood for Aquarium.
****Using a Bleach Solution
The second method is less effective than boiling, but is the best option for porous rocks. This method can also be used if the stones are too large for a conventional pot, or you don’t want to deal with the dangers of boiling rocks..
All that needs to be done with this method is to find a container where the rock can be fully submerged. The container should be filled with a 10 to 1 water to bleach solution, though some people use a slightly higher concentration.
Once it has been submerged in the bleach solution, it should be allowed to sit for 24 hours. At the end of this time, the rock should be removed, and washed thoroughly with clean water. The rocks should be rinsed under tap water, and then dipped in a bucket of treated water to remove any trace of the bleach solution.