-Contains Tannins and Humins which give Alder Cones its natural antibacterial and antifungal properties – Acidify the water which will slowly lower the pH level – Shrimp will also eat the cone as it breaks down -Biofilm will accumulate on the cone which is another great food source for shrimp. – Rinse before adding to your tank or cover with boiling water for 5-10min to reduce tannins and to ensure that it will sink immediately. – 1 cone for every 20L/ – You may add or replace after 1-2 months.