Substrate - Sand Vs Gravel

What Type of Substrate Should I Use in my Tank?

Types of Aquarium Substrate


Gravel – Gravel is the most popular type of aquarium substrate and it is also one of the least expensive. Aquarium gravel comes in a variety of shapes, sizes and colours so you can choose to go for a natural look with your tank or try something a little more colourful. When it comes to providing a place for beneficial bacteria to live, gravel is the most recommended type of substrate. Because organic wastes like uneaten fish food and fish waste can quickly accumulate in aquarium gravel, it is wise to vacuum the gravel once a week to prevent the build-up of toxins like ammonia. If you plan to use gravel as substrate in a planted tank, consider adding a layer of plant fertilizer beneath the gravel to provide plants with the nutrients they need to grow and thrive.

Sand – While not quite as popular as gravel, sand is the preferred substrate of many aquarium hobbyists. One of the main benefits of sand as an aquarium substrate is that it looks natural – if you want to simulate the natural environment of your fish as nearly as possible, sand is a good substrate to use. Unlike gravel, sand has a tendency to compact which means that organic wastes and debris will accumulate on the surface, making cleaning easier. Though sand looks very attractive in the home aquarium and it is generally considered to be cleaner than gravel, there are some drawbacks associated with its use. Because sand is so fine, it can easily be sucked up the intake tube of your filter. If you plan to use sand as the substrate in your tank, be sure to adjust the flow of your filter so it doesn’t get clogged with sand.


Plant Substrate – While it is possible for aquarium plants to live when rooted in gravel or sand, plants are more likely to thrive when these substrates are combined with some kind of fertilizer or plant substrate. Some of the most popular types of plant substrates include fluorite, laterite and vermiculate. Fluorite is a lightweight clay-like substance whereas vermiculate is a mineral substrate. Laterite is also a clay-like substance and it contains iron-oxide, a chemical which attracts and stores nutrients where plants can access them. In order to utilize 


plant substrates most effectively, place a 1-inch layer at the bottom of your tank and cover it with sand or gravel.


Tips for Aquarium Substrate


Though there are a variety of aquarium substrates to choose from, not all of them are recommended for use in the home aquarium. Peat moss, for example, is made of decaying plant matter and it can stain the water and increase the tannin content. Marine substrates such as sea sand, aragonite sand and crushed coral are also not recommended for freshwater tanks. These substrates may contain impurities or microscopic organisms that can pollute tank water. Some of these substrates may also raise the pH in your tank beyond the preferred level.

No matter which type of substrate you choose, it is important to rinse it thoroughly before adding it to your tank. Commercial substrates like sand and gravel may contain dirt or dust which can cloud the water in your aquarium. To make sure the substrate is clean, pour it into a plastic bucket or colander and rinse it with warm water until the water runs clear. Never wash substrate using very cold or very hot water because it could alter the temperature in your tank when you pour it in.