Seachem Onyx Sand – 3.5 kg – Pack of 4

Seachem Onyx Sand is a dark gray substrate that enhances the appearance of any aquarium, while providing iron and other essential minerals for healthy plant growth. This carbonate-rich sand is ideal for use in freshwater planted aquariums, but can be used in any aquarium environment. It is most effective when used on its own as an integral substrate bed, but can be mixed with other substrates if desired.

Onyx Sand is not chemically coated or treated, but does have a slight buffering capacity that may raise pH by 0.1 – 0.5 pH units. This premium substrate will last the life of your aquarium and never needs replacement. It is pre-washed, but should be rinsed prior to use to remove any residual dust particles. Slight initial cloudiness is to be expected, but will clear with 12 hours.