Aquatic Arts 50 Alder Cones | Shrimp Aquarium Decorations |pH Reducer & Buffering Water Treatment |Freshwater Fish Tank Supplies/Accessories Releases tannins that help prevent fungal infections and fight bacteria Lowers and buffers pH; perfect for lowering pH gently and naturally Produces ideal water conditions for acidic loving animals Each alder cone is about a half inch to 1 inch in length A great alternative to pH lowering driftwood such as cholla wood