Shop / Products / Estes Spectrastone Lake Green Gravel Estes Estes Spectrastone Lake Green Gravel Weight: 5 lb $15.99 Sorry, this product is currently out of stock. Information Ingredients Spectrastone lake green 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