Possible answers:
[A]. Mixing gravel with water in the tank could look creepy or behavior-altering and your fish might become offended. Organic gravel is also available at your local pet or aquarium supply store..
[B]. Be sure that the fish tank gravel you chose is safe for fish tanks. It should indicate this on the packaging and say that it is pre-washed..
[C]. Buy gravel at a local hardware or recycling store. If you can find a gravel that is at least 12 inches (30..
[D]. For freshwater pearls, choose gravel that has gentle chump and salts when targeting saltwater. For saltwater pearls, look for pearl pearls..Choose from options above and answer: What most naturally follows?

How to prepare fish tank gravel
Select the type of gravel to put in your fish tank at your local pet or aquarium supply store.
Fish tank gravel comes in several varieties, such as glass, hard gel or stone, and may be natural or dyed. For the best results, look for natural gravel or varieties with a polymer seal so it is not likely to alter your tank's chemistry and harm your fish or other aquatic life.
Answer:
[B].