Boyd Chemi-Pure Blue provides all the benefits of original Chemi-Pure, tailored specifically for the needs of marine and reef aquariums. This proprietary blend of low-dust, pelleted, activated carbon in a nylon bag is an all-in-one media that provides superior filtration to keep your water crystal clear. Premium activated carbon plus high grade ion-exchange resins. All-in-one filter media in a nylon bag. Specially designed for marine and reef aquariums. Chemi-Pure Blue features a highly effective blend of activated carbon and high capacity ion-exchange resins that significantly reduces organic compounds, waste, and phosphates, while raising redox and maintaining a stable pH in saltwater aquariums.Additional Benefits: Creates positive neurological environments of fish. Mimics a natural environment. Removes dissolved organics, coppers, metals, odors and phenol. Supports a healthy appetite and increases fish life span. Eliminates osmotic shock. Prevents ion antagonism. 4-6 month shelf life. Size: 5.5 oz.