There are 13 nutrients needed for plants to thrive. These nutrients can be added to low-tech planted tanks easily and without fertilization.
Organic potting mix or soil can be safely used in freshwater planted aquariums. They contain an abundance of beneficial nutrients for plants.
Organic dirt can be safely used as an aquarium substrate when it is capped with 2-inches of inert sand or gravel. It’s also important to establish a nitrogen cycle before adding fish and to try not to uproot plants after they’ve been planted.
Regular organic dirt is an excellent substrate option for planted freshwater aquariums. It contains high concentrations of plant nutrients and is often less expensive than commercial aquasoils. However, careful attention must be paid to which soil you buy and how you use it in your tank.
2-inches of dry sand is a sufficient cap for a dirted aquarium. This is thick enough to prevent too much ammonia from leeching into the water column. It will also create an anoxic zone on the bottom layer to promote the growth of anaerobic denitrifying bacteria.