Shop / Litter & Accessories / Estes Spectrastone Blue Gravel Estes $14.99 Estes Spectrastone Blue Gravel Quantity Weight 5-lb Ship to me Pickup in store Add To Cart Due to supply chain constraints affecting inventory levels on some brands and products, it is possible that this item may be cut. We apologize for this inconvenience and will automatically refund any items not shipped. Information Ingredients Spectrastone blue gravel is an ideal substrate for fresh water and marine tanks. Our standard colors use silica quartz which is an inert stone that will not affect pH. N/A Customers also liked Customer Reviews