Choosing aquarium gravel from hundreds of different types and styles can be quite a challenge for any aquarist. The type, style, color, or texture you choose can make a big difference in your aquarium's look and water chemistry.
Gravel is a type of substrate used to cover the bottom of the aquarium. They can be used for essentially decorative purposes. If you are trying to create a certain theme for your aquarium, like a pebbly African system or a sandy Amazon ecosystem, making the right choice of gravel is important. Aquarium gravel can also be used to aid in the filtration system or to maintain water pH.
Among the many aquarium gravel types, pea gravel is the most commonly used and the cheapest, too. The pea type is the best pick when choosing aquarium gravel for planted systems and aquariums equipped with under gravel filters. They usually come in 3 mm and 6 mm sizes, with larger sizes being less common as these grains have greater tendency to allow debris to fall in between them, thus decaying and affecting water quality. Choose pea gravel that is lime free so it would not affect water chemistry. A word of caution, though, a large quantity of pea gravel being sold is not lime-free unless specified otherwise. Also opt for the pea gravel type that is inert so it won't affect the water's ph and hardness. If you are building a tropical aquarium, try to make sure that your pea gravel is free of traces of sea shells to avoid adverse effects.
If you intend to create a coldwater, brackish, or marine aquarium system, then coral gravels will make a suitable pick when choosing aquarium gravel. Porous and completely natural, coral gravels usually come in 5 mm sizes and make for a good biological filter substrate for systems with under gravel filter. When choosing aquarium gravel, keep in mind that coral gravels tend to create harder, alkaline water for your system, so make sure that your fish can thrive in these conditions.
Want to create a more striking and modern-type aquarium system? Then selecting quartz gravel as your substrate can create a more dramatic effect. Quartz gravel come in jet black color and is a perfect choice when choosing aquarium gravel that can easily go well with other aquarium plants and decorations.
If you have a small aquarium, then you might want to light it up with the different hues and colors of colored gravels. There is a range of vibrant colored gravels in the market, and make sure that you choose ones that are safe and do not easily leach color. Pick epoxy-coated ones as they are safer and more inert.
Regardless of type, aquarium gravel needs regular maintenance by vacuuming to remove uneaten food and other debris. Also try to do away with deep layers of gravel substrate where food particles can sink in and eventually produce substances that are toxic to fish. Also check out cultured gravels as they can significantly help in biologically balancing and naturally removing debris from your aquarium. Choosing aquarium gravel, just as maintaining an aquarium, requires a balancing act from any aquarist.
