Tourmaline based nano-cubes that produce long-lasting clarity for freshwater and marine aquariums. 8 blocks treats up to 400L / 100 Gal Clarifies aquarium water without the mess The Maxspect Nano-Tech Clear Cube is a tourmaline-based brick that breaks down DOM (dissolved organic matter) in aquarium water by dissolving and dissociating of water as a result, keeping your aquarium water clearer for an extended period of time as compared to granular activated carbon. Features • Breaks down dissolved organic matter (DOM), removing the yellow color in an aquarium. • Long lasting effect, water stay crystal clear for longer. • Helps combat cyanobacteria and other nuisance bacteria/Fungal in your aquarium.