How to Apply Bentonite in Your Pond: A Complete Guide

Bentonite is a type of clay that has been used for centuries as a natural filtration system in ponds. This mineral-rich clay is a popular choice among pond owners because of its ability to absorb and filter out harmful chemicals, algae, and waste products from the water. In this article, we will explore how to apply bentonite in your pond effectively.

What is Bentonite?

Bentonite is a type of clay that is rich in minerals such as calcium, magnesium, and potassium. It was first discovered in the 19th century in Montmorillon, France, and is now widely used around the world. Bentonite is highly absorbent and has a unique structure that allows it to trap and filter out contaminants from water.

Benefits of Bentonite in Ponds

Bentonite offers several benefits when applied to ponds, including:

  1. Chemical filtration: Bentonite is highly effective at absorbing and filtering out harmful chemicals such as chlorine, chloramines, and heavy metals from the water.
  2. Algae control: Bentonite can absorb and remove algae from the water, helping to keep your pond clear and healthy.
  3. Wastewater filtration: Bentonite can help filter out organic waste and other debris from the water, keeping it clean and crystal-clear.
  4. pH regulation: Bentonite helps maintain a stable pH level in the water, which is important for the health of your fish and aquatic plants.

How to Apply Bentonite in Your Pond

Applying bentonite to your pond can be done in several ways, including:

  1. Mixing the bentonite with water and spreading it evenly over the bottom of the pond. This method is ideal for large ponds and requires specialized equipment.
  2. Using a pre-mixed bentonite product that can be added directly to the water. These products are easy to use and require little maintenance.
  3. Adding bentonite to the filtration system of your pond. This method is ideal for smaller ponds and requires less maintenance than other methods.


  1. How much bentonite should I use in my pond? The amount of bentonite needed depends on the size and type of pond. As a general rule, you will need 2-3 pounds of bentonite per 100 gallons of water.
  2. When should I apply bentonite to my pond? Bentonite can be applied at any time of the year, but it is best to apply it before the growing season of your aquatic plants.
  3. Can I mix my own bentonite? Yes, you can mix your own bentonite by combining equal parts of bentonite and water in a blender until a smooth paste forms.


In conclusion, bentonite is an effective natural filtration system for ponds that can help keep the water clean and healthy. By following these simple steps, you can apply bentonite to your pond effectively and enjoy the benefits of this powerful mineral-rich clay.