Instructions
Collect rocks of various sizes and colors; searching nearby bodies of water, parks and other natural environments. Think about what will fit in your aquarium and make for good surroundings for your aquarium pets. Gather as many rocks and pebbles as you need.
Remove all moisture from inside the rocks by drying them in a warm place for a week or more. Set them in a corner of your home, or in a sunny spot on your porch. Exposing your rocks to heat and warmth will ensure that they don't crack or explode while in hot water.
Place a large pot atop a gas burner or outdoor grill. Alternatively, you can use a pot on your kitchen stove, but make sure to open windows and air out the room, if you do this indoors. Fill your pot with your rocks, up to 75 percent of your pot's capacity, so there is room for the water. Pour warm water over the rocks, until they are fully submerged. Turn the heat on high, to start the water boiling. Let your pot sit for an hour or more. Whenever water evaporates below the surface of the rock, add more.
Cool your rocks by replacing the boiling hot water with cold tap water. Rinse them thoroughly after they've sat on the burner for at least an hour. You can feel free to move your rocks into the aquarium once they are cool to the touch.
How to Boil Rocks to Disinfect
Experts are divided on the issue of boiling rocks for use in fish aquariums. If you choose to stock your own aquarium without synthetic products from pet stores, you'll need to find rocks and stones from a local pond, park or river. Boiling these found items is one effective way to disinfect them for the sake of your pets' health and comfort. The boiling process will remove all bacteria and parasitic insects from the surface of the rocks.