Description
Our high-purity sodium bentonite fines in a convenient 1.2 tonne FIBC (Flexible Intermediate Bulk Container) bulk bag. Sourced directly from Australian mines.
The 1.2 tonne bulk bag is the most cost-effective way to purchase bentonite for medium to large farm dam sealing projects, effluent pond lining, landfill containment, and commercial earthworks applications.
Calculated coverage: At Bentonite Pro’s recommended application rate of 30 kg/m², one 1.2 tonne bulk bag provides material for 40 m² before any allowance. This is an ordering calculation, not a guarantee of sealing. Confirm soil suitability, the cause of leakage and the installation method before treatment. See How It Works for method guidance and limitations.
Bentonite bulk bags at a glance
| Item | Detail |
|---|---|
| Bag size | 1.2 tonne (1,200 kg) FIBC bulk bag with lifting loops |
| Product | Sodium bentonite fines, nominal particle size under 1.25 mm |
| Price per tonne | $295 + GST, before freight |
| Price per 1.2 tonne bag | $354 + GST ($389.40 including GST) |
| Coverage per bag | 40 m² at the recommended 30 kg/m² |
| Delivery | Road freight to NSW, VIC and QLD addresses, confirmed before the order is accepted |
| Unloading | Forklift or telehandler required on site |
| 25 kg bags | Not sold. Bentonite Pro supplies bulk bags only |
How many bentonite bags do I need?
Multiply the area you will treat, including the floor and sloping walls, by the recommended 30 kg/m², then divide by 1,200 kg and round up to whole bags.
| Area to treat | Bentonite at 30 kg/m² | Bulk bags | Product cost ex GST |
|---|---|---|---|
| 100 m² | 3.0 tonnes | 3 | $1,062 |
| 250 m² | 7.5 tonnes | 7 | $2,478 |
| 500 m² | 15.0 tonnes | 13 | $4,602 |
| 1,000 m² | 30.0 tonnes | 25 | $8,850 |
| 2,000 m² | 60.0 tonnes | 50 | $17,700 |
Use the bentonite quantity calculator for your own area, and the transport calculator for an indicative freight estimate.
Bentonite bags: common questions
How much does a bag of bentonite weigh?
Each Bentonite Pro bulk bag holds 1,200 kg (1.2 tonnes) of sodium bentonite fines. Retail bentonite is also sold in 25 kg bags, which take 48 bags to make up the same 1.2 tonnes.
Are bulk bags cheaper than 25 kg bentonite bags?
Yes, per tonne of material. Bentonite Pro charges $295 a tonne before GST and freight. Retail 25 kg bags listed online in October 2026 cost about $640 to $1,000 a tonne before freight.
How are bentonite bulk bags delivered?
Bulk bags travel by road freight to NSW, VIC and QLD addresses. Freight is calculated to your delivery address and confirmed before an order is accepted. You need a forklift or telehandler and safe truck access to unload them.
Where to buy sodium bentonite for dams
Bentonite Pro sells sodium bentonite fines direct in 1.2 tonne bulk bags for farm dams, ponds and earthworks across NSW, VIC and QLD. Bentonite Pro charges $295 + GST per tonne, so each bag is $354 + GST before freight. Retail 25 kg bags listed online in October 2026 cost about $640 to $1,000 a tonne before freight, so bulk bags suit dam-scale jobs. The sodium bentonite delivered price guide sets out the price per tonne, coverage per bag and how freight to your address is calculated.
Read before you order
- Buying bentonite: a farm dam order checklist
- Farm dam leaks: causes to check before buying bentonite
- Bentonite application rate for sealing a dam or pond
- How to apply bentonite to reseal a leaking dam
- Why sodium bentonite is the right choice for dam sealing
Need the leak diagnosed or the treatment installed rather than material alone? Our parent company, the Big Ditch Dam Building Company, inspects and repairs farm dams.
Typical physical properties
As-is basis, from the Big Ditch Bentonite spec sheet.
- Montmorillonite content: >90%
- Cation exchange capacity: >90 meq/100 g
- Swell index: 7 to 16 mL/2 g
- pH: 5 to 7.5
- Moisture content: 12 to 20%
- Bulk density: 1.2 to 1.4 t/m³
Fine-grade particle size
- Nominal particle size: <1.25 mm
- Upper limit tolerance: retained on 2 mm, 5% maximum by weight
- Lower limit tolerance: passing 75 µm, 15% maximum by weight
Typical chemical properties
Oven-dried basis (105°C), XRF.
- Silica (SiO2): 61.5%
- Alumina (Al2O3): 18.5%
- Soda (Na2O): 1.3%
- Magnesia (MgO): 5.2%
- Lime (CaO): 0.1%
- Potash (K2O): 1.3%
- Ferric oxide (Fe2O3): 4.1%
These are typical values for general information, not guaranteed specifications. View the Big Ditch Bentonite spec sheet (PDF) for the full technical information and disclaimer.
Country of origin: Australia
Packaging: 1.2 tonne FIBC bulk bag with lifting loops
Freight note: Bulk bags are delivered by road freight. Forklift or telehandler required for unloading. Please ensure site access before ordering. Contact us for freight quotes to remote areas.