Natural mud ponds are lined with bentonite to seal them. It was also discovered that feeding small quantities to koi and occasionally bathing then in it or adding regulated dosages to the pond resulted in wonderful and significant effects on their color and luster. Montmorillonite can be easily added to your daily ration of food. This is an excellent idea as it will replicate the koi feeding continuously off minute mineral rich particles on the floor of mud dams. For the koi hobbyist montmorillonite is used directly in the pond water each week in the recommended dosage.
Some types disperse more easily than others.
Some have to be mixed with water before application whilst others can be sprinkled directly onto the pond surface. The pond will clear in about 6 - 10 hours, depending on the amount of organic material in the pond, but the montmorillonite will remain active. Do not be worried in a new pond if the water does not clear in a day or two. Also the clay can be mixed with the food. Coat damp pellets lightly with montmorillonite.