While at work the other day i noticed some smooth gravel called plumbers rock (quater minus is the stock name) and was thinking of using it in my tank. the only question i had was how can i clean this rock and make it safe for my fish tank. im quite sure all it would need is a good rinse but wanted to check before i use it. i also have some river stones wich have been sitting in the garden for years. can i wash these and then put them in or should i boil them for a couple of minutes first?
