Coloured Gravel

Aquarium gravel comes in many sizes, shapes, colors and materials. Unless you are using a UGF (Underground Filter) or have a planted tank, gravel is not essential and is primarily used for aesthetic purposes. You will notice we do not use gravel in our tanks within the shop,and many quarantine or hospital tanks do not use any substrate, making it easier to clean the debris. Natural gravel, epoxy coated gravel and tumbled glass are the materials primarily used for aquarium gravels. Most of the natural gravels used in freshwater aquariums are quartz or granite.

Avoid coral, sea shells, dolomite and limestone based materials. These will release carbonates in the tank raising its pH buffering capacity. A simple test to determine if your gravel is inert and will not affect the pH is to drip an acid such as vinegar on the gravel. If it foams or bubbles it is not inert and will leach carbonates and affect the pH.

All gravel should be washed thoroughly prior to use. Epoxy or plastic coated gravel should never be boiled, as this will loosen the coating.
Usually the darker gravels will show the fish colors best. The lighter gravels tend to give a washed out color to the fish.

If you are using a UGF filter then you will want 5 to 8 cm of gravel on top of the filter plates. The nitrifying bacteria adheres to the gravel providing the biological filtration. 8 to 12 cm can be used for planted tanks. This will provide support for plant roots and depth for planting.

Terracing the gravel by having it deeper in the back and slowly lowering to the front will provide depth for the aquarium and help in cleaning as the debris will tend to collect in the front, making it easier to remove with a gravel vacuum. Over time the gravel will tend to even out. To prevent this terracing with rocks or slate will help keep the gravel in place.