The aquarium substrate is generally the first step when setting up your empty freshwater fish tank. You must have some kind of substrate if you want to keep water plants, give your aquarium a natural look, and add driftwood, rocks, or other decorations to your tank.
The substrate is very important for the well being of the fish tank because it affects the water quality or you will not have a functioning fish tank.
Unless you use a fish tank for auxiliary purposes like for quarantine or raising fry, you definitely need aquarium substrate.
The aquarium substrate acts as a natural filter by collecting the organic waste that falls down; is a source of food for the aquarium plants, and imitates the natural fish habitat.
Types of aquarium substrate
Your aquarium substrate can be gravel, sand, dirt, crushed marble, or artificial substrate. Artificial substrate can be imitation gravel with a natural look and colors or it can be made of small chunks of blue, pink, black, or other colors, though some aquarists look down upon this as poor taste.
Whatever substrate you choose, always avoid sharp shaped gravel to prevent your fish from injury.
If you use natural gravel, you can add fertilizers to improve the growing of the plants. Also, you can add other kinds of substrate that affects the pH and hardness values of the water.
For example, you can add peat if you want soft acidic water or crushed corals to make the water harder with an increased alkaline.
The gravel can be small or larger in size, from a few millimeters to 1 cm or more.
Larger gravel is easier to clean using an aquarium gravel cleaner by siphoning the water with the gravel cleaner; the gravel chunks fall down most of the time before the gravel cleaner sucks them, unlike sand in which you would need to circle with your finger or other tool, get the water dirty and wait for the organic waste to settle and then siphon the waste.
Common aquarium substrate facts
The most common fact about aquarium substrate is the type of aquarium determines the type of substrate. It all comes down to what type of aquarium you would like to have.
For example, if you want an Amazon-type of aquarium, you need to use gravel, ground dirt, and peat. If you want a Malawi cichlid aquarium, sand, rocks, and even crushed corals will make the water more suitable for the African cichlids.
If you want a community tank rich with water plants, you could use gravel, ground dirt, or other organic soils. Plants feed by absorbing nutrients and minerals with their roots (microorganisms help as well), so the substrate should be rich enough for the plants to grow large, strong, and beautiful.
The aquarium substrate can be added in layers and areas. When it comes to areas, be creative by constructing different areas of substrate, like darker soil in one bigger area and or yellow sand in another region of the tank.
A useful tool when placing substrate is utilizing a common wall paintbrush to give the substrate a smooth look.
If you use layers, generally the largest gravel goes on top and the substrate should be at least 2 inches or about 5 cm thick for healthy plant roots and sufficient growth.
Also, the same rule of thumb should be used as when planting water weeds, which is placing the substrate lower in the front and higher in the back of the fish tank for optimal visual view. Larger objects, like rocks or driftwood, usually are set in the back to prevent blocking of the view.
When it is time to add the water, use a plate, deep dish, or other item to prevent stirring your substrate, so it can keep the shape you gave it.
Commercial aquarium substrates
If you want to be sure your water plants will have enough nutrients from the aquarium substrate, research new commercial products out on the market.
There are companies that produce, pack, and sell good quality aquarium substrates in various-sized bags. The good quality brands contain nutrients, minerals, and organic compounds the water plants require.
The commercial substrates are packed and labeled for the type of aquarium you need and include detailed instructions.