BENTONITE FOR SEALING PONDS
Sodium Bentonite clay swells up to eighteen times its dry size when it becomes wet. Expanded bentonite forms an impermeable gel seal which makes an excellent pond sealant. Bentonite is environmentally safe and does not affect the water, livestock, or wildlife. When properly applied, it will not harm fish. For these qualities, bentonite also makes an excellent liner for new pond construction.
When sealing a leaking pond to prevent water loss through seepage, Bentonite can be applied directly to the soil in the pond bottom or it can be sprinkled on the surface of the water and allowed to settle to the bottom. There are three basic methods: the blanket method, the mixed blanket method and the sprinkle method. Bentonite is easily applied. In the case of small ponds, it can be applied with simple hand tools and for larger ponds, with ordinary farm equipment.