Alder cones provide an ideal environment for shrimp to grow and molt safely. They are also highly beneficial for bio-filtering in the aquarium. They help to remove organic waste and clear the water. Alder cones are also known to have anti-fungal and anti-bacterial properties which help to keep the aquarium clean and healthy. Alder cones help greatly when hatching eggs and rasing fry each bag contains around 20-25 cones giver or take.