Onyx™ is a specially fracted porous substrate for the aquarium. Onyx™ is suitable for any marine or freshwater environments and is ideally suited for cichlid environments. Onyx™ is most effective when used alone as an integral substrate bed, but it may be mixed with other gravels or sands. Onyx™ is not chemically coated or treated but does have a slight buffering capacity.

Although pre-washed, it may be rinsed before use to remove residual dust. Dust can also be minimized by filling aquarium slowly and dispersing water so that the Onyx™ bed is not disturbed. Slight initial cloudiness is normal and will clear rapidly (2–12 hours). To shorten the cloudiness period use Clarity™ in conjuction with mechanical filtration (such as filter floss). To determine the number of bags required for your aquarium, please note that each bag (7 kg, 15.4 lbs) occupies a volume of approximately 7,000 cm³ (425 cu. in.).

Sizes: 7 kg (15.4 lbs) bag

Wondering how many bags you will need for your project? It's easy to figure out with this gravel calculator. Just enter the length and width of your aquarium along with the desired depth of the substrate and click calculate. Note: The calculator will always round up. For example, you can't pruchase 1.3 bags, so it will return 2 bags.