Lava Rock (Coarse Grade)

For the largest aroids with thick, strong roots lava rock may be the appropriate choice for that super chunky substrate mix. Its porosity lends itself to well-draining mixes. Lava rock is also often used as drainage and/or as the sole substrate in terrariums where the plants don’t require a high level of nutrients.. Lava rock is also great drainage material for vivariums. Lava rock is a great substrate that has a high surface area making it an ideal filter/drainage material that won't break down quickly. We recommend covering lava rock with a material such as horticultural fabric or synthetic screening to prevent smaller-grained substrate materials from filtering down into it.. Lava rock is also an excellent biological filter. The large surface area lends itself to a high volume of beneficial bacteria, Nitrosomonas and Nitrobactercomes, that will convert ammonia into nitrite and nitrite into nitrate respectively.. 20-30mm Grade