Description

Rock Alum– Heavy-Duty Pool Flocculant & Coagulant

Product Data

Attribute	Verified Information
Product Name	Rock Alum
Chemical Category	Coagulant / Heavy-Duty Flocculant
Active Ingredient	Aluminium Sulphate (Al₂(SO₄)₃·18H₂O — hydrated form)
Chemical Formula	Al₂(SO₄)₃
Alternative Names	Alum; Aluminium Sulfate; Aluminium Alum; Filter Alum; Paper Maker’s Alum; Liquid Alum (liquid form)
Primary Purpose	Heavy-duty coagulation of fine suspended particles for severe water clarity problems. Particularly effective for extremely turbid or green water.
Typical Usage	Severely cloudy pools; post-algae recovery; commercial pools; water treatment plants; industrial water clarification

Rock Alum – Heavy-Duty Pool Flocculant & Coagulant

Product Overview

Rock Alum is a heavy-duty coagulant and flocculant containing Aluminium Sulphate (Al₂(SO₄)₃·18H₂O) in traditional lump or chunk form. It is used for severe water clarity problems, particularly effective for extremely turbid or green water that standard clarifiers cannot resolve.

Rock Alum is the traditional commercial and agricultural form of Aluminium Sulphate, typically sold as large lumps or chunks which are dissolved for use. It operates identically to granular aluminium sulphate flocculant — forming aluminium hydroxide colloids that coagulate suspended particles. The product is widely used in drinking water treatment plants (one of the oldest water clarification methods), where its use is governed by standards such as NSF/ANSI 60 for drinking water treatment chemicals.

Rock Alum and Flocculant (granular aluminium sulphate or PAC) share the same active ingredient and mechanism. Rock Alum is the traditional lump/rock form, while the Flocculant product may be granular or PAC. Both require vacuuming to waste post-treatment.

How It Works

Rock Alum works through the same coagulation and flocculation mechanism as granular aluminium sulphate, with the lump form requiring crushing or dissolving before use.

The coagulation process involves:

• Dissolution – Rock Alum lumps dissolve in water, releasing aluminium ions
• Hydrolysis – Aluminium ions hydrolyse to form positively charged aluminium hydroxide colloids (Al(OH)₃)
• Charge neutralisation – Positively charged colloids attract negatively charged fine suspended particles
• Coagulation – Particles bind together into larger masses
• Flocculation – Coagulated particles aggregate into larger, denser flocs
• Settling – Flocs sink to the pool floor due to increased density

The lump form requires physical crushing or extended soaking time before complete dissolution, making it less convenient than granular forms but often more cost-effective for large-volume applications.

Why It Matters

• Severe water clarity problems require heavy-duty solutions. When standard clarifiers fail and water remains turbid or green, Rock Alum provides the coagulation power needed to resolve the issue.
• Post-algae recovery often leaves dead algae cells suspended in the water, causing persistent cloudiness. Rock Alum removes these cells effectively, completing the recovery process.
• Cost-effective heavy-duty treatment is provided by Rock Alum. The lump form is often more economical than granular flocculants, particularly for large-volume applications or water treatment plants.
• Water treatment applications extend beyond pools. Rock Alum is widely used in drinking water treatment plants, industrial water clarification, and wastewater treatment.
• Proven technology with a long history. Aluminium sulphate has been used for water clarification for decades, with a well-documented safety and efficacy record.

Key Benefits

1. Very Cost-Effective
   Rock Alum is an economical option for heavy-duty coagulation, particularly for large-volume applications.
2. Powerful Coagulant for Heavy Contamination
   Effectively coagulates and settles even the most stubborn suspended particles, resolving severe turbidity.
3. Widely Available
   Available from multiple sources including agricultural suppliers and water treatment distributors.
4. Long Shelf Life
   Rock Alum has an indefinite shelf life when stored dry, making it suitable for stockpiling.
5. Proven Technology
   Used for decades in water treatment with a well-documented safety and efficacy record.
6. Suitable for Severe Cases
   Effective where standard clarifiers and granular flocculants have failed.

Problem-Solution Table

Problem	Likely Cause	How Rock Alum Helps	Expected Outcome
Extreme water turbidity	Heavy particulate suspension	Heavy-duty coagulation and settling	Clear water
Heavy algae residue after treatment	Dead algae cells in suspension	Removes suspended algae cells	Complete recovery
Failure of standard clarifier	Particles too fine or numerous	More powerful coagulation	Effective particle removal
Persistent cloudy water	Fine colloidal particles	Removes fine colloidal matter	Crystal-clear water
Industrial water clarification	Heavy particulate load	Cost-effective particle removal	Clarified water

Dosage & Application Guidance

Dosage requirements vary depending on manufacturer specifications, pool volume, contaminant load, water chemistry, bather load, environmental conditions, and treatment objectives. Always follow product label instructions and professional water test results.

Based on the reference guide, typical guidance includes:

• General guidance: 250–500 g per 10,000 litres for heavy coagulation
• Method: Dissolve before adding or broadcast directly
• Filter setting: Set to recirculate
• Settling time: Allow 12–24 hours to settle
• CRITICAL: Vacuum to waste — do not backwash into filter

Important: Rock Alum requires crushing or dissolving before use. Recheck pH and alkalinity after treatment — aluminium sulphate is acidic and will lower pool pH.

Water Balance Reference Table

The values below represent general swimming pool industry guidance and are not specifications of the product described on this page. Actual operating targets may vary depending on local regulations, pool type, water source, equipment design, and operating objectives.

Parameter	Recommended Range	Notes
pH	7.2–7.6	Rock Alum is acidic — recheck after treatment
Total Alkalinity	80–120 mg/L	Rock Alum affects alkalinity — recheck after treatment
Free Chlorine	1.0–3.0 mg/L	Normal chlorine levels before treatment

Step-by-Step Application Guide

Before Treatment:

1. Test pool water for pH and total alkalinity
2. Ensure chlorine levels are normal (1.0–3.0 mg/L)
3. Crush Rock Alum lumps into smaller pieces for faster dissolution if possible
4. Calculate required dosage based on pool volume
5. Gather required PPE: gloves, safety goggles, protective clothing

During Treatment:

1. Option A (Pre-dissolve): Dissolve crushed Rock Alum in a bucket of pool water
2. Option B (Direct addition): Broadcast crushed Rock Alum directly over pool surface
3. Set filter to ‘Recirculate’ (bypass filter media)
4. Allow 12–24 hours for particles to settle
5. Do not swim during treatment

After Treatment:

1. Vacuum settled floc to ‘Waste’ — DO NOT backwash into filter
2. Refill pool with fresh water if significant water was lost
3. Recheck pH and alkalinity — Rock Alum is acidic and will lower both
4. Adjust pH and alkalinity as needed using pH Plus and pH Plus Super
5. Resume normal filtration

Troubleshooting:

• Lumps not dissolving: Crush into smaller pieces; allow more time
• Particles not settling: Check circulation — may need more time or additional product
• Pool still cloudy after vacuuming: Repeat treatment if necessary
• pH too low: Use pH Plus to raise pH after treatment

Usage Guide for Kenya & East Africa Region

• Severe Turbidity Events
  Kenya’s rainy seasons and dust storms can introduce heavy particulate loads that overwhelm normal filtration. Rock Alum provides the heavy-duty coagulation needed for these events.
• Post-Algae Treatment
  During warm, rainy seasons, severe algae blooms require heavy-duty recovery. Rock Alum is effective for removing dead algae cells after treatment.
• Water Treatment Applications
  Beyond pool use, Rock Alum is used in drinking water treatment plants in Kenya and East Africa. Agricultural suppliers often stock it for various water treatment applications.
• Commercial Pool Recovery
  Hotels and resorts with severe water clarity issues benefit from the cost-effectiveness of Rock Alum for heavy-duty clarification.
• Coastal Pools
  Coastal areas with high humidity and salt spray may experience persistent turbidity. Rock Alum provides a cost-effective solution.

Commercial Applications

• Hotels, Resorts & Safari Lodges
  Commercial pools experiencing severe turbidity benefit from Rock Alum’s heavy-duty coagulation power and cost-effectiveness.
• Water Treatment Plants
  Rock Alum is widely used in municipal and industrial water treatment for clarification.
• Industrial Water Clarification
  Industries requiring water clarification for process water or wastewater treatment use Rock Alum.
• Agricultural Applications
  Agricultural water treatment for irrigation and livestock water uses Rock Alum.

Residential Applications

• Private Pools
  Homeowners with severe water clarity issues can use Rock Alum as a cost-effective heavy-duty treatment.
• Holiday Homes
  Properties returning to discover severely cloudy pools benefit from Rock Alum’s powerful clarification.

Safety & Handling

Storage Conditions

• Store in a dry, cool location
• Keep away from alkalis
• Shelf life: Indefinite when stored dry
• No significant fire or explosion hazard

Personal Protective Equipment (PPE)

• Gloves
• Safety goggles
• Protective clothing when crushing or handling dust

Mixing Precautions

• Avoid strong alkalis
• Do not combine with high-pH chemicals during treatment
• Avoid inhalation of dust

Spill Response

• Sweep up dry product
• Rinse spill area with water
• Use appropriate PPE

First Aid

• Inhalation: Move to fresh air
• Skin contact: Wash with soap and water
• Eye contact: Rinse with water for at least 15 minutes
• Ingestion: Rinse mouth; seek medical attention

Important Safety Disclaimer

The safety information contained here is provided for general reference purposes only. Always refer to the official Safety Data Sheet (SDS) and Technical Data Sheet (TDS) provided by the product manufacturer before handling any chemical. Local health, safety, and environmental regulations must be observed at all times. The dosage guidance provided is indicative only — always test pool water and adjust dosages based on actual test results.

Product Comparison

Feature	Rock Alum	Flocculant (Granular)
Form	Lump/chunk	Granular or liquid
Active Ingredient	Aluminium Sulphate (hydrated)	Aluminium Sulphate or PAC
Preparation Required	Crushing/dissolving required	Ready to use (granular dissolves readily)
Cost	Generally more cost-effective	More expensive
Best Application	Heavy-duty, large volume	All flocculation needs

Cross-Selling Recommendations

• Algaecide
  For green pool recovery, use algaecide first to kill algae, then Rock Alum to remove dead algae cells.
• Chlorine 65% (Calcium Hypochlorite)
  Shock treatment before Rock Alum oxidation improves flocculant effectiveness.
• pH Plus (Sodium Carbonate)
  Rock Alum is acidic and lowers pH. pH Plus restores pH after treatment.
• pH Plus Super (Sodium Bicarbonate)
  Rock Alum affects alkalinity. pH Plus Super restores alkalinity after treatment.

FAQs- Rock Alum

1. What is Rock Alum used for in swimming pools?
   Rock Alum is a heavy-duty coagulant containing Aluminium Sulphate used for severe water clarity problems, particularly effective for extremely turbid or green water.
2. How is Rock Alum different from regular Flocculant?
   Rock Alum is the traditional lump/rock form of Aluminium Sulphate, while Flocculant is typically granular or liquid PAC. Rock Alum requires crushing before use but is generally more cost-effective.
3. How much Rock Alum should I add to my pool?
   Typically 250–500 g per 10,000 litres for heavy coagulation. Always test water and follow label instructions.
4. Does Rock Alum affect pH?
   Rock Alum is acidic and will lower pool pH. Recheck and adjust pH after treatment.
5. Can I swim after adding Rock Alum?
   The pool should be taken out of service during treatment. Resume swimming after vacuuming and water balance correction.
6. Do I need to vacuum Rock Alum after treatment?
   After treatment, vacuum settled floc to ‘Waste’ — do not backwash into the filter.
7. Is Rock Alum safe for pool surfaces?
   When used correctly, Rock Alum is safe. However, strong acidic solution can etch surfaces if applied in high concentration directly. Always pre-dissolve or broadcast evenly.

Summary / Conclusion

Rock Alum is a heavy-duty coagulant containing Aluminium Sulphate in traditional lump form, used for severe water clarity problems. It is the traditional commercial and agricultural form of Aluminium Sulphate, operating identically to granular flocculant but requiring crushing before use. Cost-effective for large-volume applications, it effectively removes suspended particles through coagulation and flocculation. Requires vacuuming to waste after treatment and pH/alkalinity correction due to acidic nature. Widely used in pool recovery, water treatment plants, and industrial clarification. Suitable for severe cases where standard clarifiers have failed.

Need Rock Alum for your pool or facility?

Vinsol Kenya is your trusted supplier of swimming pool chemicals and water treatment solutions across Kenya and East Africa. Whether you manage a hotel pool, school facility, waterpark, or residential pool, we have the products and technical expertise to keep your water crystal clear and safe.

Contact us today for bulk orders, commercial supply contracts, or expert technical advice.

• 📞 Call/WhatsApp: +254 715 01 45 10
• 📧 Email: inquiries@vinsol.co.ke | info@vinsol.co.ke
• 📍 Ruiru Branch: Next to Total Petrol Station – Kihunguro, Ruiru
• 📍 Eldoret Branch: Rehema Complex, opposite Japara Ltd., along Oloo Street, Eldoret
• 🕐 Working Hours: Mon – Sat 8:30AM – 5PM

References:

1. Publisher Source: World Health Organization (WHO)
   Article Title: Guidelines for Safe Recreational Water Environments, Vol. 2: Swimming Pools and Similar Environments
   URL: https://www.who.int/publications/i/item/9241546808
   Access Date: August 4, 2026
2. Publisher Source: Centers for Disease Control and Prevention (CDC)
   Article Title: Healthy Swimming: Pool Chemical Safety
   URL: https://www.cdc.gov/healthywater/swimming/
   Access Date: August 4, 2026
3. Publisher Source: NSF International
   Article Title: NSF/ANSI Standard 50: Equipment for Swimming Pools, Spas, Hot Tubs and Other Recreational Water Facilities
   URL: https://blog.ansi.org/ansi/nsf-ansi-50-2025-equipment-swimming-pools/
   Access Date: August 4, 2026
4. Publisher Source: Pool Water Treatment Advisory Group (PWTAG)
   Article Title: Swimming Pool Water: Treatment and Quality Standards for Pools and Spas
   URL: https://www.pwtag.org/standards/
   Access Date: August 4, 2026
5. Publisher Source: American Chemical Society (ACS)
   Article Title: The Chemistry of Swimming Pool Maintenance
   URL: https://pubs.acs.org/doi/10.1021/ed084p1124
   Access Date: August 4, 2026
6. Publisher Source: PubChem (National Library of Medicine)
   Article Title: Aluminium Sulphate – Compound Summary
   URL: https://pubchem.ncbi.nlm.nih.gov/compound/Aluminum-sulfate
   Access Date: August 4, 2026
7. Publisher Source: International Organisation for Standardisation (ISO)
   Article Title: ISO 15714: Method of Evaluating the UV Dose to Airborne Microorganisms
   URL: https://www.iso.org/obp/ui/#iso:std:iso:15714:ed-1:v1:en:fig:1
   Access Date: August 4, 2026