The Signs of Poor Substrate in a Planted Aquarium

Live aquarium plants require as much care as any other plant, including plant-specific nutrients that need to come from the substrate they are planted in. Difficulties arise when the substrate is inadequate for the plants that are used in the aquarium. It's always best to research the type of plants before acquiring them and get to know what types of substrate are ideal for that particular aquatic plant.

  1. Plants Fading and Dying

    • Aquatic plants demonstrate their preferences for certain types of substrates. When the wrong one is used, the plant in question will show it by fading out to yellow or developing dark spots on its leaves. This means the plant is dying and something needs to be added to the substrate quickly. Research the particular plant and find out which types of aquatic fertilizers are the best for that plant before the plant dies and rots.

    Lack of Root Anchoring

    • When a rooted plant begins to detach from its place in the substrate and floats on the surface, deeper substrate needs to be used for that plant. If the roots are long, the plant won't stay anchored if there isn't enough substrate used. Eventually the fish will knock some of the substrate away from the roots and pouring more on top or raking the grains back in place helps to keep the plant where it belongs.

    Potting Soil and Buoyancy

    • Using potting soil as the substrate in aquariums presents a problem, as there are buoyant materials in potting soil, such as perlite and bits of wood, both of which will float in water. The fish may try to eat these floating objects and may get them caught in their throats. Also, potting soil contains fertilizers which can poison the fish and cause more harm than good with aquatic plants that require different nutrients than earthbound plants.

    Substrate Compacting

    • Substrates deliver nutrients best when they are light and airy, rather than compacted. Similarly, ground soil that is compacted by foot traffic becomes hard and nothing grows up through it. Compacted substrate won't release the nutrients, making the plants suffer. All substrates get packed down eventually, but adding trumpet snails to the tank helps as they burrow into the substrate, keeping it oxygenated and releasing toxins. Also, raking the substrate lightly releases toxins and oxygenates the layers.