Volcanit is a pH-neutral aquarium gravel of volcanic origin developed specifically for use in modern live-plant aquaria. The fine pore structure of this structure encourages bacterial activity that enhances the biological release of nutrients from within the gravel. The results are superb plant growth. Volcanit is mixed with 10% ferrolit, a natural long term iron fertilizer derived from Laterite. The resultant black and red colors enhance the beauty of the aquarium plants and the hues of the tenant fish.