Poly Aluminium Chloride (PAC) & Alum

What is poly aluminium chloride (PAC)?

Poly aluminium chloride is a pre-polymerised aluminium coagulant. When it is added to water, its positively charged aluminium species neutralise the negative charge on clay, silt, colour and other fine particles, so they clump together into flocs that can settle or be filtered out.

Because PAC is already partly polymerised, it works faster than conventional alum, works across a wider pH range, consumes less alkalinity, and usually produces less sludge. It is commonly followed by an anionic polyelectrolyte to build larger, faster-settling flocs.

PAC vs alum: which should you use?

The cheapest coagulant per kilogram is not always the cheapest per litre of treated water. A jar test with your water shows which one gives clear water at the lowest total cost, including pH correction chemicals and sludge disposal.

Our inorganic water treatment chemicals

How PAC is dosed

1. Dissolve powder PAC in clean water to make a solution, or use liquid PAC directly or diluted.
2. Dose at the rapid-mix point (flash mixer or inlet channel) so it spreads through the water in seconds.
3. Add polyelectrolyte afterwards in the slow-mix zone if you need bigger flocs.
4. Set the dose by jar test and adjust with changes in turbidity, for example during the monsoon.

Who uses our coagulants

• Municipal and township water plants
• Housing societies and commercial complexes
• Effluent treatment plants and CETPs
• Sewage treatment plants
• Swimming pools
• Paper and pulp
• Textile and dyeing
• Food processing
• Construction and tunnelling water
• Mining and sand washing

Grades and specifications

Typical values for each grade we supply. Technical data sheet and safety data sheet available on request.

Poly Aluminium Chloride (PAC) & Alum: product range

Each product line has its own page with uses, dosing guidance and FAQs.

• Alum (Aluminium Sulphate)
• Ferric Chloride

Frequently asked questions

What is poly aluminium chloride used for?

Poly aluminium chloride (PAC) is a coagulant used to remove turbidity, colour, suspended solids and some organic matter from drinking water, effluent and sewage. It is also used in swimming pools and in paper and textile processes.

Is PAC better than alum?

PAC usually forms flocs faster, works over a wider pH range, lowers pH less and produces less sludge than alum. Alum costs less per kilogram. Which is more economical depends on your water, so a jar test is the best way to decide.

Is PAC a coagulant or a flocculant?

PAC is a coagulant. It neutralises the charge on fine particles so they can stick together. A polyelectrolyte flocculant is often added afterwards to build bigger flocs.

Can PAC be used for drinking water?

Yes, PAC is widely used in drinking water treatment. Use PAC that meets IS 15573, dose it correctly and follow with filtration and disinfection, keeping residual aluminium within the IS 10500 limit. Ask us about the grade for your application.

In what form do you supply PAC?

We supply PAC as a powder in bags and as a liquid in cans, drums and bulk, so you can choose what suits your storage and dosing system.

How much PAC should I use?

The dose depends on your raw water turbidity, colour and pH, and changes with the season. A jar test gives the right dose; tell us about your water and we can help you plan one.

What is the HSN code for poly aluminium chloride?

Poly aluminium chloride is generally classified under HSN 2827 (chlorides). Confirm the exact code and GST rate on our invoice or with your tax adviser.

Can PAC be used in swimming pools?

Yes. PAC is used in pools as a coagulant and clarifier to remove fine cloudiness, working with the filter. For home pools see our pool care range.

Does PAC change the pH of water?

PAC lowers pH and alkalinity less than alum, but it still consumes some alkalinity. Check pH after dosing, especially in soft, low-alkalinity water.