*Demily High Quality Activated Carbon Filtration 500g -High Absorbent It can eliminate the smell and yellow substance in the water efficiently, and decomposing dissolve organic substances, Carbolic acid and tannic acid, and the residual chlorine in tap water. -No Impurities Activate carbon has a neutral Ph value and has no impact on water quality. -Best for freshwater and saltwater aquariums Functioning with mechanical filter materials can prolong its life of durability. *Demily High Quality Bio-Ring Glass 350g -Made from natural Silicate at a high temperature. Its stable chemical characteristics accord with the primitive living environment of microorganisms. -The Multi-porous Structure provides a 6 to 8 times larger surface compared to other ordinary bio-rings. The high adhesion density of microorganisms contributes to the best filtering effect. -Best for freshwater and saltwater aquariums Functioning with mechanical filter materials can prolong its life of durability. *Multi-Zeolite 500g -Natural matter Stable Ph value to soften the effect of water quality, such as deorant. -Absorbing harmful substances Absorbing and removing the suspended materials in the water and the rotten filthy on the bottom to prevent from fish diseases. -Effective clean water quality Decomposing various viruses, ammonia, nitrite, hydrogen sulfate, etc. Best of freshwater and saltwater aquariums.