mdb_talon;2545601; said:I would worry about the sealants and oils that are commonly used on granite countertops.
Woodworm;2576074; said:If you think that there might be any chemicals in the pieces of granite that you have, there are a few things that you can try to remove them. (I have worked in the countertop industry before.) I personnely think that the small amout that might leach out at any one time will not effect your tank with proper filtration and water changes.
1. Boil them if they are small enough. If you go with this method put the pieces in room temperature water and slowly bring them up to a boil then let them boil for about 10 minutes. Turn off and let the water and the rocks come back down to room temp (rocks will take longer to cool). Drain and rinse well with tap water. Repeat twice. Don't rush the heating or cooling steps as it may lead to cracking.
2. Soak in strong vinegar solution (I recomend agriculture vinegar it has a higher acid percentage) let it soak for 24 hours then rinse well. Once should be enough.
3. Leave it outside in the weather for a year. The weather will do all the work.
Hope this helps.
Liam;2576273; said:not sure he wants to wait a year, though.
oh, wouldn't you just use HCl if you wanted a high % of acid?