NYOS® REEF CEMENT is a rapid adhesive with a firm grip and is low in harmful substances, which can be used to attach corals, overhangs, columns and complete stone structures easily and durably. REEF CEMENT is a powdery substance, which is simply stirred in cold water and cures completely within 2 minutes. Can be used above and below water Not harmful to corals or fish Attachment of corals, columns, reef structures, etc. Corals can be attached on the reef structure either as over-hanging or free-standing corals. Is soon overgrown with coralline red algae