There are hundreds of ways that you can make your aquarium “your own”, from the decor or theme you choose to the plants and fish you keep, and even how you choose to accent your habitat with lighting. You may spend a lot of time anguishing on these aspects, hoping to match the vision you build in your head. One aspect that you may not guve the consideration it deserves is the substrate you choose, but the right gravel can make or break the look of your aquarium. This stuff is more than just rocks and sand, it may be the one thing that completes your perfect aesthetic. Let’s look at some of the popular substrate options on the market and explore why one may suit your aquarium better than others.
If you have a freshwater aquarium, you have a huge selection of substrate colors and types to choose from. First you have to decide if you’re going for a natural look or for something more thematic or colorful. You can purchase colored pebbles or glass accent stones in every color of the rainbow, but some colors are so vibrant they can take the attention away from the stars of the display, your fish. Colored stones have their place, and can make for a realy fun set-up, but be sure you know what you’re getting into before you purchase a bulk of neon pink or blue substrate. Often these substrates are best as accent colors mixed with natural selections, or for use in smaller tanks.
The natural look tends to be more desirable amongst most hobbyists, shades of grey, tan and brown. These pebbles mimic the textures of creak beds, river shallows, and other natural habitats where these fish come from, making them feel like their back at home. While not all that eye-catching in a bag, these substrates complement the natural colors of live fish and plants, really allowing them to shine. These selections aren’t monotonous either. There are lots to choose from, different sizes, multi-tone, tumbled or rough, that can be mixed or matched to create a custom blend for your tank. Keep in mind that the size of the gravel you choose may have some impact on fish and plants. Bottom dwelling or bottom feeding fish, and those who breed and nest in the substrate will generally prefer sand or very small pebbles that are easier to move and shuffle, and softer on fins, skin and scales. Likewise, plants may not root well in pebbles that are too large or rough. You may choose to create varying areas in the tank between larger pebbles and finer substrate like inert sand to accommodate several types of fish and plants. Inert types of freshwater sands are available, but be sure to choose the right kind, otherwise your water chemistry could be effected.
There are also special substrates you can use in your freshwater tanks that not only look natural but also provide benefits to your livestock. These include packaged live sand, flourite/laterite plant substrates, soils and cichlid substrates. Live sand is harvested from a natural wet environment and is packaged with live bacteria intact. These bacteria jump start the cycling process and help to establish marine tanks fast. Plant substrates are naturally colored and sized just right for root establishment. These materials also contribute nutrients to enhance plant growth and vigor. Several substrates on the market are designed to cater specifically to the chemistry and habitat need of Rift Lake Cichlids. These help to maintain pH and hardness, and mimic the rocky appearance of their natural habitats. Some hobbyists also go to the next level for Asian and Amazonian species by creating a soft soil/sand bed using peat, laterite or coco fiber. The natural feel and tannin production helps to make these light-shy fish more comfortable and can make their colors super vibrant.
Marine substrates include shell, crushed coral, aragonite sand and similar materials principally composed of calcium carbonate. These substrates will help to increase and maintain pH and hardness. These materials are suitable for all marine set-ups and for Rift Lake cichlids that enjoy similar water chemistry minus the salt. These substrates present little variation from afar, with mostly cream or white coloration with flecks of pink, orange and other naturally occurring shell coloration. There are a few selections that occur naturally in gold or black hues which may be mixed with lighter varieties or used as primary substrate. Incorporating these darker colors may help to keep the colors of your fish more vibrant, as the bright bottom may cause the colors of the fish to appear washed out.
In some instances you may even choose to go bare in the aquarium. Bare bottom is usually reserved for med tanks or quarantine systems, but many aquarists opt for no gravel to make maintenance and feeding easier. While this type of set-up has advantages, there are several things to consider before going bare. Some fish may stress easily or not be able to behave naturally if there is no substrate to cover the bottom glass. This method is obviously not a good choice if you want to house gobies or other bottom dwelling or burrowing species. Rooted live plants will not have a place to anchor without a deep gravel bed, so you’ll also be limited to either artificial plants that suck to the bottom or bunch plants that do not need to be anchored in gravel. Substrate also provides a large bed for nitrifying bacteria…be sure to have ample biological filtration, porous rock, or other media to offer the bacteria a place to thrive.
What it all boils down to is taste. The gravel you choose will complete your aquarium’s look and can play a big role in how your fish behave in the tank. Consider the needs of your fish before you make the final decision on how to “carpet” your tank.