Whether caused by the elements or an accident, pond leaks are sometimes an unavoidable problem. When left unattended, a small leak can spread, causing your pond to drain partially or completely, harming wildlife and plants. Often used in cosmetics, bentonite clay expands to several times its original size when exposed to water, and is an effective and safe way to seal any holes or cracks in your pond.
Drain the remaining water from the pond with the attached pump, or use a submersible pump, available at hardware and home improvement stores, attached to a garden hose. Remove any debris, rocks and plants from the pond's bottom. Because it's difficult to discover the leak's source many times, you should apply the bentonite to the entire floor of the pond.
Sprinkle the bentonite over the bottom of the pond. The Penn State College of Agricultural Sciences Cooperative Extension recommends applying the sodium bentonite clay at a rate of 1 pound for each square foot. Wear a dust mask and gloves while applying the sodium bentonite to avoiding inhaling the product. which can also cause skin irritation.
Work the bentonite clay into the top 3 to 4 inches of the pond floor with a hoe or rototiller. If the surface area of the pond floor is small, a hoe is acceptable. However, a rototiller is more effective if the area is large, as incorporating the bentonite is a labor-intensive job.
Refill the pond immediately after spreading the and incorporating the bentonite clay. Because the dry bentonite will begin to slowly shrink, Penn State warns this could result in cracks, and future leaks in the pond. If you cannot fill the pond immediately, cover the floor with a 1- to 2-inch layer of mulch or straw to prevent the bentonite from drying.
Things You Will Need
- Submersible pump
- Garden hose
- Dust mask
- Mulch or straw (optional)
- Sprinkling bentonite clay over the pond while it still has water is another method sometimes tried, although Penn State cautions this is rarely effective. The theory is that the bentonite will sink to the bottom and fall into and seal the leaks. Although this is less labor-intensive, the results aren't always effective or long-lasting.
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