Pond Leak Sealant (Bentonite, 50 lb Bag)

Pond gypsum helps clear muddy water by causing suspended clay particles to settle. Granular bentonite absorbs water and swells to help seal pathways where water escapes through pond soil. Choose gypsum for suspended-clay cloudiness and bentonite to help seal subsurface leaks and surface cracks in pond soil and earthen pond dams. They serve different purposes and aren’t interchangeable.

Our granular bentonite can be applied in standing water to target seepage through suitable pond soil. Locate the leak first and plan the application area. Application may require multiple bags or repeat applications, depending on the size of the area and severity of the seepage.

Start with what you can see around the pond. You don’t need to measure an underwater area to begin a targeted application.

• If you know the exact leak location, try one 50 lb bag of granular bentonite concentrated around that spot as an initial application. Larger leaks may require additional bags.
• If you see seepage on the outside of the pond dam, begin on the pond side opposite that location. Spread the granules over the suspected entry area. Water can travel through soil before appearing outside, so use the visible seepage as a starting clue.
• If the location is uncertain, work in marked sections along the suspected shoreline. Place rocks or bricks on the bank to show where each application begins and ends. Keep track of the bags used and watch the water level before expanding to the next section. This helps you avoid missing areas or repeatedly covering the same spot.

For a clearly located leak, one bag gives you a practical first step. When the source is uncertain, expect to use multiple bags as you work through the suspected areas. Keep a consistent water-level marker so you can judge progress while accounting for rain and evaporation.

Work in small, marked sections with our granular bentonite. If you can see seepage outside the dam, start on the pond side opposite that location. Otherwise, begin along the suspected shoreline.

Use a scoop, such as an ice scoop, to broadcast the dry granules evenly from the bank over the section you’re covering. In our own applications for uncertain leak locations, we visually estimate enough material to form roughly a half-inch layer over that area. This is an estimate of the material spread, rather than a layer you can see or measure underwater.

Mark the beginning and end of each section with rocks or bricks before moving to the next area. Keep track of the bags used so you can identify where you’ve applied material and avoid gaps or unnecessary overlap.

Watch your water-level marker and any visible seepage over the following days to assess progress before applying more.

For a localized leak, a targeted granular bentonite application lets you focus on the suspected area and evaluate the pond’s response before expanding the work. Plan enough material to cover that area at the recommended application rate; spreading a small amount too thinly may not provide an effective seal. Some ponds need multiple bags or repeat applications. Start with a defined area and a clear application plan so each purchase supports the next step.

Keep your granular bentonite completely dry until application. Do not let rain, sprinkler water or other moisture reach it before use. Bentonite absorbs water and swells, turning the dry granules into clumps or a sticky mass that you cannot spread as intended. Prevent this by keeping it dry from delivery until application. Store bags under cover and off damp ground. Reseal opened bags or transfer the remaining material to a dry, watertight container.

Send us your pond’s approximate size, how quickly the water level drops, and photos of any suspected leak areas. Let us know whether the pond is full, partially drained or empty, and whether you know the soil type. These details help us give you a useful starting point for evaluating granular bentonite and planning your purchase. Email brent@newallafishcompany.com before ordering if you’d like help getting started.

Finding the likely leak area helps you put granular bentonite where it can do the most good and plan how much material you’ll need. Watch where the water level stabilizes, look for wet areas outside the pond, and note any visible cracks or seepage. You don’t need to have every answer before getting started. Send us your observations and photos at brent@newallafishcompany.com, and we’ll help you evaluate the next step before you invest in a bentonite application.

Email brent@newallafishcompany.com with the product name, selected size and quantity, destination ZIP code, and the exact checkout message. A missing rate can have more than one cause, including a destination restriction or shipping setup issue. Use your actual delivery address while we review it.