Whats the best substrate for planted aquarium with fish?
For larger tanks, using only specialised planting substrate could be really very expensive unless you’ve bottomless pockets. The reason for using such specialised substrates is to provide constant & long term nutrient needs for plants, primarily those who mainly take in nutrients via the roots and plants who need more iron. For the majority of planted tanks & with a more modest budget, different layers of substrate are used, may be up to 4 layers. The total substrate depth should be about 2.4 – 4 in (6-10 cm), the min & max depth should be sloping from front of the tank to the back (also make it slightly undulating to look natural). Too deep and you will have more compacting problems with inadequate aeration of the lowest parts (substrate will turn black). Those who use a heating cable will need a base substrate of very fine granularity (about 0.04 in or 1mm), sand is ideal but only enough to just cover the cable. Most people will start with a main rooting substrate as the bottom layer
