Weco Wonder Shells are a 50 year old hobby classic. The wonder shells proved several uses. For instance, this is the most decorative way to remove chlorine from your fish tank. Just drop one in and all the chlorine is instantly removed.
Most importantly - made of natural materials, Wonder Shell provides beneficial minerals and electrolytes to aquarium water. Each shell oxygenates, aerates and neutralizes harmful acids in your aquarium water and provide invertebrates with an easily available source of calcium for health shell growth.
One large shell treats 20 gallons for one month.
Shipping Size: One each in small pack (Small bag fits in any live fish box)