plant aquarium soil consists of two components:
At the bottom of the aquarium, there is typically a plant medium with a minimum thickness of 1 cm. The plant medium is a nutrient-rich substance, the roots of the plants come here in a dense, nutrient-rich medium. Some of the professional plant media – due to the larger particle size – help with bacterial development and balance in the aquarium.
There is a minimum of 4 cm of general plant soil layer on top of the plant medium. This fired clay-based soil prevents the plant medium from coming into direct contact with the water column and provides ideal conditions for the roots of the plants. The roots only feel good in clay-based soils, sand or gravel are not suitable for plants … These sterile substrates are only used for decorative purposes in plant-based aquariums.
The soil of a planted aquarium plays a much more important role than we might think. In addition to being important for rooting plants, it is of paramount importance in performing biological screening of the aquarium. A well-assembled soil – for decomposing ammonia – is almost at least as important as a costly external filter. It has been shown countless times that an established aquarium can continue to function without algae, even after a major power outage, when most of the bacteria in the filter are likely to have died, most likely due to the right quality of soil – and thus the bacteria growing in it.
Soil is therefore also important for the overall balance of the aquarium. In order to give the nitrifying bacteria a suitable surface, it is necessary that the oxygen required for the bacteria be present everywhere, so the soil must remain an oxygen-rich environment. This requires a sufficiently large particle size.
From the line of reasoning, it is already clear why fast-compacting, fine-grained sand is not suitable for aquarium soil. Tiny grains of sand impede the movement of water in the soil and soon an oxygen-poor, i.e. anaerobic, environment develops in the soil. And in an anaerobic environment, the exact opposite of nitrification, denitrification will take place, i.e. ammonia will be formed – which is by no means a desirable condition in a planted aquarium.
The role of the plant as a medium and general plant soil in biological filtration is so important that in our experience it is important to use it, for example, when designing an aquarium that does not have plants that can be planted in the soil, such as mosses, ferns or other stones our aquarium.
The thickness of the plant soil can vary within the aquarium to achieve the proper visual effect. Typically, plant aquariums tend to raise the soil level from the front to the back, often to a level that can even reach the water surface along the back wall. Extremely good quality soils are needed to prevent the grains from “rolling down”.
Inferior, cheaper soils are usually characterized by lighter soil grains. This makes it extremely difficult to plant in them – with the exception of the planting tweezers, the soil grains do not compress the roots and the plant easily comes out of the soil, or the soil cannot be “hilly” efficiently as the lighter grains slip over each other and “collapse the structure”. The grains of professional soils are heavier, contain more nutrients, buffer water parameters, and are more hilly.
Better soils run out slowly, we don’t have to worry about having to reorganize our aquarium in 1-2 years. A well-designed system is viable for years. The soil can only be replanted by completely dismantling the aquarium, so we recommend using quality materials from the very first minute.
How much soil will I need?
Calculating the amount of plant medium is simple: multiply the sides of the base of the aquarium in cm and divide the product by 1000. This gives the required amount of plant medium in liters. And the minimum amount of general plant soil will be four times this value. If we want to raise the ground backward like a hill, we have to buy several bags of soil. The Plant Soil Calculator XLS, developed by the Green Aqua team, helps us calculate how much soil we will need.