Choosing the substrate for your Tank

A substrate is the material at the bottom of the tank.  The substrate serves to anchor the plants in the aquarium.  It also serves to conceal the uneaten food and dirt at the bottom of the tank.

It also adds to the aesthetics of the tank. Choose a substrate which fits with the scheme of colors in the tank.  Some substrate tend to eclipse the fish.  The substrate should complement the aquarium and bring out the beauty of the plants and the fish.  Look at different types of aquarium and their substrates before deciding a substrate for your aquarium.

There are many different substrates to choose from Gravel and sand are the most common substrates.


There are many types of gravel in varying sizes and colors.  Gravel is simple and easy to clean.  It does not irritate fish, particularly those species which love to scoop the substrate in their mouth.  Gravel is available in large and small sizes.  Large sizes may create spaces in between in which food and other particles can accumulate.  However, larger gravel sizes are easier to clean.

Crushed Coral

Crushed coral has the effect of increasing the pH due to the calcium carbonate which is the primary constituent of shells and corals. This is used for fish species such as cichlids which are used to a higher pH level and hard water in their native environment.  Crushed coral should not be used for fish used to a lower pH and soft water such as those from the amazon.


Sand is used to give a natural look to the aquarium.  Sand is ideal for species which like to build nests. Other species such as stingrays like to bury themselves in sand.   There are many different types of sand available.

One of the disadvantages of sand is that it is difficult to clean.  When siphoning the aquarium, sand gets vacuumed along with the dirt.

Sand also tends to compact over a period of time.  This 'caking' effect needs to be periodically broken to ensure a fine texture.

Peat is made of decomposed vegetable matter.  Peat is the natural substrate in many parts of the amazonia from which most tropical fish hail.  Hence, if you want an aquarium mimicking the amazon basin, you can consider Peat.  Peat tends to color the water slightly brown.  Peat has good anti-microbial properties and is ideal for live plants.

There are also many other artificial substrate which are fertilized to support live plants.  These can be purchased at your nearest pet store.