Sodium Bentonite Clay PELLETS - Sealer for deep Ponds Lakes and Bore holes

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Available sizes
SizePrice ex VATPrice inc VAT
5Kg £17.49 £20.99
10kg £24.58 £29.49
10x25kg £301.24 £361.49
40x25kg £646.66 £775.99
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Sodium Bentonite PELLETS


Bentonite is used in foundry, metallurgy, well drilling slurry, oil, agriculture. Bentonite is also used in chemical industry, environmental protection, zoology construction, ecological construction, building, paper making, textile. Bentonite also can be used in printing & dyeing, ceramics etc.  

This clay is Civil Engineering grade and suitable for use in engineering projects where a slower absorption of water and swelling is preferred. It is commonly used for sealing bore holes, deep ponds, lakes etc (see below). 


properties of Bentonite Clay:

  • CAS No: 1302-78-9
  • EC No: 215-288-5
  • Other names: sodium Bentonite, Montmorillonite, Aluminosilicate of sodium
  • Appearance: Pellets ( 1 cm approx )
  • Colour: Tan
  • Odour: mild
  • Bulk Density: 1050 Kg/m3

When bentonite is mixed with water, the water molecules will enter between the clay plates, forcing them apart. While the plates are dispersed, the bentonite slurry becomes quite fluid. However, on standing the particles become oriented with the negative surfaces of the plates being attracted to the positive edges. Viscosity increases and a gel is formed – a reversible effect known as thixotropy.

A typical empirical formula for bentonite is:

(Al, Fe0.67 Mg0.33) Si4O10(OH)2Na,Ca0.33



  • Sealing ponds, lakes and landfills (more information below)
  • Well drilling slurry.


Bentonite Pellets For Sealing Ponds:

Sodium Bentonite Pellets swell 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.

When sealing a leaking pond to prevent water loss through seepage, Bentonite Pellets can be applied by sprinkling on the surface of the water and allowing to settle to the bottom. In the case of small ponds, it can be applied with simple hand tools and for larger ponds and lakes, with ordinary farm equipment.


Click here for further information on how to apply bentonite:


Application Rates:
  • Clay soils: 5-7 Kg/m2
  • Sandy Silt: 10-12 Kg/m2
  • Silty Sand: 12-15 Kg/m2
  • Clean Sand: 15-20 Kg/m2
  • Rock or Gravel: 20/25 Kg/m2


Click here for MSDS

Click here for the Specification sheet


PLEASE NOTE: This product is not for human or animal consumption.