Nutrient substrate for plants
Active substrate that releases nutrients for the roots of aquatic plants. Essential for densely planted aquariums with demanding plants.
Detailed explanation
Nutrient substrates (soil) are the basis for a successful planted aquarium. Unlike inert gravel, they deliver nutrients directly to the roots.
ADA Amazonia is the most famous substrate. Lowers pH, releases ammonia initially and lasts 1-2 years. Tropica Aqua Soil is the European alternative with less ammonia release.
UNS Controsoil, Dennerle Scaper's Soil, Fluval Stratum are other good options.
The alternative to active soil is inert substrate with a fertile bottom. A nutrient layer is laid covered with 3-5 cm of inert gravel.
Active soils deplete over time (1-2 years). It can be integrated with root tabs fertiliser capsules.
Do not use nutrient substrates in unplanted aquariums: the nutrients released feed the algae.