Manufactured Sand (M-Sand) for Concrete -Properties and
Sand And Substitutes For Sand Screening. When sand contains lumps or stones it should be screened, or, if required of great fineness, passed through... Washing. Sand found to contain impurities, such as clay, loam, etc., which unfit it for almost every purpose, should be... Examination Of Sand. ...Feb 20, 2020 Though, many experienced aquarists say that crushed coral is a better refugium substrate than sand because larger spaces allow the water to flow and will trap fewer nitrates. The good thing is, if you can keep nitrate levels under control, the crushed coral will help the microfauna grow and breed.