• Made of Natural Materials
• Easy to Use 
• Adds Essential Minerals to Aquarium Water

These shells are great for adding hardness and minerals into your aquarium water. If you need more minerals for snails, shrimp, plants, goldfish or African cichlids etc, Wonder Shells are a good place to start. They are extremely easy, just drop it in your aquarium. Over time, Wonder Shells will completely dissolve into your water. Simply replace them when they do.

What size shell you need depends on your aquarium. We recommend testing your water and adjusting based on water change schedule.

Some loose guidelines:

• 3 Pack (1/2 Ounce) - 1 shell per month for 5 to 10 gallon aquariums.
• 2/5 Ounce - 1 shell per month for 20-30 gallon aquariums.
• 1 1/3 Ounce - 1 shell per month for 40 to 55 gallon aquariums.
• 2 1/4 Ounce - 1 shell per month for 75 and larger aquariums.