However, using your own gravel or stones in the bottom of the aquarium comes with some inherent risks if you don't first test the stones. Rock composition could possibly change the hardness and pH of the water in a way that harms your fish. Collected outdoor stones may also be covered with contaminants that can affect aquarium water.
Aug 14, 2019· Sandstone, simply put, is sand cemented together into rock — this is easy to tell just by looking closely at a specimen. But beyond that simple definition lies an interesting makeup of sediment, matrix, and cement that can (with investigation) reveal a great deal of valuable geologic information.