Proper substrate is essential for plants development. When preparing substrate we have to remember few things, to make it right. I will try to describe them below.
The substrate in the aquarium should be loose allowing water to flow freely through all the layers reaching the roots of plants, in the dense substrate anaerobic decomposition of organic residues occurs.
Keeping substrate worm will stimulate root development. You can used for this purpose waterproof heating cables or use a double bottom.
Excess calcium increases the hardness of the water. That is why you should not use calcareous sand and gravel. Quartz gravel is the best solution.
If the soil is too bright reflected light can have negative influence on well-being of fish.
Bottom: very small, well-washed gravel or dark coarse sand mixed with an appropriate fertilizer - a minimum of 5 cm, top: gravel with a diameter of 3-8 mm thickness about 2 cm.
Bottom: sand or gravel from clean rivers or lakes -not washed, top: a well-washed fine gravel.
Bottom: very fine gravel mixed with clay balls (do not mix the clay with sand, because it will slime the water in the aquarium.) or with balls of clay containing tablets of fertilizer for plants, top: a well-washed gravel or sand.
Plants are planted in plastic containers with perforated bottom, filled with a mixture of garden soil, sand and clay.
Substrate the same as for beginning aquarists, but top layer should be boiled and rinsed peat.
Even if we have purchased our substrate in the store we still need to clean it properly before use. To do this, pour gravel into a bucket, (half its height) and immerse a rubber hose, so that warm water can pass through the entire layer the gravel. We must constantly stir the gravel. Then remove the water with bits we do not want in the gravel. Repeat the action several times. Next step is to pour a boiling water into the bucket with the gravel. It would be good to see whether our gravel contains calcium. To do that prepare small sample and add some vinegar or other weak acid such as hydrochloric acid. If the foam will appear it means that this gravel contains calcium.
For decorations, you can use aquarium stones (pebbles for example), pieces of rock (basalt, granite, etc.), roots (alder, willow), coconut shells, pots or houses bought in a pet shop. Shell is not recommended to be used because it increase water hardness. Please note that all of these items must be boiled before use.