Description

Chlorine 65% – Calcium Hypochlorite Pool Sanitiser

Product Data

Attribute	Verified Information
Product Name	Chlorine 65%
Chemical Category	Sanitiser / Disinfectant / Shock Chlorinator
Active Ingredient	Calcium Hypochlorite (Ca(OCl)₂)
Chemical Formula	Ca(OCl)₂
Alternative Names	Cal Hypo; Calcium Chlorohypochlorite; Granular Chlorine; Shock Chlorine; Pool Chlorine
Primary Purpose	Primary pool water sanitisation and shock treatment. Kills bacteria, viruses, and algae through the release of hypochlorous acid (HOCl) upon dissolution.
Typical Usage	Daily chlorination; superchlorination (shock treatment); commercial pools; municipal pools; hotel pools; hospital pools; school pools

Chlorine 65% – Calcium Hypochlorite Pool Sanitiser & Shock Treatment

Product Overview

Chlorine 65% is a granular calcium hypochlorite swimming pool sanitiser and shock chlorinator used for primary pool water disinfection and superchlorination. It is an inorganic hypochlorite salt containing 65% available chlorine by weight, making it one of the most concentrated solid chlorine compounds in common pool use.

Calcium Hypochlorite (Ca(OCl)₂) is manufactured by chlorinating calcium hydroxide (slaked lime) and is classified as a UN Class 5.1 oxidising solid. When dissolved in water, it undergoes hydrolysis to produce hypochlorous acid (HOCl) — the primary biocidal species responsible for disinfection — and calcium ions (Ca²⁺).

This product is widely used across commercial pools, waterparks, municipal pools, hotels, hospitals, schools, and water treatment facilities. It is also suitable for residential pools when handled correctly.

How It Works

Chlorine 65% works through a straightforward chemical process. When calcium hypochlorite granules are dissolved in water, the compound hydrolyses to release hypochlorous acid (HOCl).

The disinfection process involves:

• Cell wall penetration – HOCl molecules are small and electrically neutral, allowing them to penetrate bacterial cell walls and algal membranes
• Enzyme disruption – Once inside, HOCl oxidises essential enzymes and proteins, disrupting metabolic processes
• Cell death – Microorganisms including bacteria, viruses, and algae are inactivated or destroyed
• Organic oxidation – HOCl also oxidises organic contaminants such as sweat, urine, and sunscreen residues

The pH of a calcium hypochlorite solution is alkaline (approximately 10.8), which may require pH adjustment after dosing. At typical pool pH levels (7.2–7.6), the equilibrium favours HOCl, maximising disinfection effectiveness.

Why It Matters

1. Health protectionis the primary reason Chlorine 65% matters. Without adequate sanitisation, swimming pools become breeding grounds for pathogens including  coli, Pseudomonas, Legionella, and viruses that cause gastroenteritis, respiratory infections, and skin conditions.
2. Water sanitationthrough consistent chlorination ensures that bathers are protected from waterborne diseases. The Centres for Disease Control and Prevention (CDC) identifies adequate free chlorine levels as the single most important factor in recreational water safety.
3. Swimmer comfortis directly affected by water chemistry. Proper chlorination prevents the formation of chloramines (combined chlorine) which cause eye irritation, red eyes, and the characteristic “chlorine smell” that many swimmers find unpleasant.
4. Pool longevityis extended when water is properly sanitised. Uncontrolled microbial growth can lead to biofilm formation on pool surfaces and equipment, causing staining, degradation, and costly repairs.
5. Regulatory complianceis mandatory for commercial pools. Health departments and local authorities require documented water quality monitoring and adequate sanitiser residuals. Using a reliable product like Chlorine 65% helps facilities meet these requirements.

Key Benefits

1. High Available Chlorine Content (65%)
   At 65% available chlorine, this is one of the most concentrated solid chlorine products available for pool use. This high concentration means less product is required per dose, making it cost-effective for large-volume pools and commercial facilities.
2. No Cyanuric Acid Build-Up
   Unlike stabilised chlorine products (such as Trichlor), Chlorine 65% does not add cyanuric acid to pool water. This prevents over-stabilisation (“chlorine lock”) which occurs when CYA levels exceed 80 mg/L and reduce chlorine efficacy.
3. Versatile Application
   Chlorine 65% serves dual purposes: daily chlorination and shock treatment (superchlorination). This versatility reduces the number of different chemicals a facility needs to stock.
4. Cost-Effective for Large Pools
   The high concentration and competitive pricing make Chlorine 65% an economical choice for commercial pools, municipal facilities, waterparks, and hotels.
5. Widely Available and Proven Track Record
   Calcium hypochlorite has been used for decades in pool sanitation and water treatment, with a well-documented safety and efficacy record.
6. Suitable for Pools Without UV Stabiliser Systems
   Because it does not contain cyanuric acid, Chlorine 65% is appropriate for indoor pools and pools equipped with UV or ozone systems where stabiliser is not required.
7. Effective Against a Broad Spectrum of Contaminants
   Chlorine 65% addresses bacterial contamination, algae growth, viral pathogens, combined chlorine (chloramines), cloudy water, and low free chlorine readings.

Problem-Solution Table

Problem	Likely Cause	How Chlorine 65% Helps	Expected Outcome
Green or cloudy water	Algae bloom or bacterial growth	Superchlorination (shock treatment) oxidises algae and bacteria	Clear water within 24–48 hours
Strong chlorine smell	Combined chlorine (chloramines)	Breakpoint chlorination oxidises chloramines	Elimination of odour; improved swimmer comfort
Low free chlorine readings	High bather load or UV degradation	Daily dosing maintains free chlorine at 1.0–3.0 mg/L	Consistent sanitisation
Eye and skin irritation	Chloramines or imbalanced pH	Proper chlorination prevents chloramine formation	Reduced irritation
Bacterial contamination	Inadequate sanitiser residual	Primary disinfection eliminates pathogens	Safe swimming water
Algae on walls and floor	Insufficient chlorine residual	Shock treatment and daily chlorination prevent algae establishment	Algae-free surfaces

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:

• Initial dosage (new pool or after shock): 150–200 g per 10,000 litres
• Maintenance dosage: 70–100 g per 10,000 litres daily
• Target free chlorine: 1.0–3.0 mg/L (ppm)
• Method: Pre-dissolve in a bucket of pool water before broadcasting

Important: Adjust dosages based on actual test results. Factors such as bather load, temperature, sunlight exposure, and rainfall all influence chlorine demand.

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
Free Chlorine	1.0–3.0 mg/L	Minimum 0.5 mg/L for disinfection
Combined Chlorine	< 0.5 mg/L	> 0.5 mg/L indicates chloramine issues
pH	7.2–7.6	Outside this range reduces chlorine efficacy
Total Alkalinity	80–120 mg/L	Provides pH buffering
Calcium Hardness	200–400 mg/L	Important when using calcium-based chlorine
Cyanuric Acid	30–50 mg/L (outdoor)	Not required for indoor pools

Step-by-Step Application Guide

Before Treatment:

1. Test pool water for free chlorine, combined chlorine, pH, total alkalinity, and calcium hardness
2. Ensure pH is within 7.2–7.6 range (chlorine is most effective at this pH)
3. Calculate required dosage based on pool volume and test results
4. Gather required PPE: chemical-resistant gloves, safety goggles, dust mask

During Treatment (Daily Chlorination):

1. Fill a clean plastic bucket with pool water (not fresh water)
2. Add the measured Chlorine 65% granules to the bucket water — always add chemical to water, never water to chemical to prevent violent reactions
3. Stir gently until the granules are fully dissolved
4. With the pool pump running, broadcast the solution evenly around the pool perimeter
5. Allow the pump to run for at least 4–6 hours for proper circulation

During Treatment (Shock Treatment):

1. For shock treatment, use 150–200 g per 10,000 litres (or as directed by product label)
2. Best performed in the evening or at dusk to minimise UV degradation
3. Pre-dissolve as described above
4. Broadcast across the pool surface with pump running
5. Leave pump running overnight for best results

After Treatment:

1. Retest free chlorine after 4–6 hours (or next morning for shock treatment)
2. Adjust pH if necessary (calcium hypochlorite solution is alkaline, ~pH 10.8)
3. Retest combined chlorine to confirm breakpoint chlorination has been achieved
4. Document test results for commercial compliance records

Usage Guide for Kenya & East Africa Region

• High UV Exposure
  Kenya’s tropical location means intense UV radiation year-round. Chlorine 65% is unstabilised, meaning it degrades rapidly under direct sunlight. For outdoor pools in Kenya, the reference guide specifically recommends the addition of cyanuric acid (stabiliser) to reduce chlorine degradation.
• Rainy Seasons
  During Kenya’s long and short rains, heavy rainfall can dilute pool water, reduce chlorine levels, and introduce organic contaminants. Increased chlorine demand is common during these periods, requiring more frequent testing and dosing.
• Dust and Organic Contamination
  Dust storms and wind-blown debris introduce organic matter that consumes chlorine. Facilities in arid or semi-arid regions of Kenya should anticipate higher chlorine consumption and adjust dosing accordingly.
• Coastal Pools
  Coastal areas such as Mombasa and Diani experience high humidity, salt air, and warm temperatures — all of which increase chlorine demand. Salt air can also accelerate equipment corrosion, making proper water balance particularly important.

Commercial Applications

• Hotels, Resorts & Safari Lodges
  Guest expectations for crystal-clear water are high. Chlorine 65% provides reliable disinfection for high-turnover pools. Its cost-effectiveness makes it suitable for large hotel complexes with multiple pools.
• Airbnb Properties
  Short-term rental properties require simple, effective pool maintenance. Chlorine 65% can be used for both daily chlorination and shock treatment, reducing the number of products owners need to manage.
• Schools & Universities
  Educational facilities must meet stringent health and safety standards. Chlorine 65% provides reliable disinfection for school pools used by children and young adults.
• Competition Pools & Public Pools
  Municipal and competition pools require consistent water quality to meet regulatory standards. The high concentration of Chlorine 65% makes it suitable for large-volume facilities.
• Waterparks
  Waterparks present unique challenges: high bather loads, warm water temperatures, and extensive water surfaces. Chlorine 65% is used for primary disinfection and shock treatment in many waterpark facilities.

Residential Applications

• Private Pools
  Homeowners appreciate the simplicity and effectiveness of Chlorine 65%. It can be used for routine chlorination and as a shock treatment, reducing the number of chemicals needed.
• Holiday Homes
  Properties that are occupied intermittently benefit from the long shelf life (2 years when stored correctly) of Chlorine 65%.
• Apartment Complex Pools
  Multi-unit residential complexes require pool maintenance that is both effective and cost-efficient. Chlorine 65% meets both criteria.

Safety & Handling

Storage Conditions

• Store in a cool, dry, well-ventilated area away from direct sunlight
• Keep away from flammable materials, reducing agents, and other pool chemicals
• Store in original sealed container
• Optimum storage temperature below 30°C
• Shelf life: 2 years when stored correctly

Personal Protective Equipment (PPE)

• Chemical-resistant gloves
• Safety goggles or face shield
• Dust mask or respirator (P2 rating)
• Protective clothing

Mixing Precautions

• DO NOT mix with acids – risk of chlorine gas release
• DO NOT mix with Trichlor (TCCA) – causes violent exothermic reaction, fire, or explosion
• DO NOT mix with other chlorinating agents, ammonia compounds, flammable materials, or organic matter
• Always add chemical to water, never water to chemical
• Pre-dissolve before adding to pool

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	Chlorine 65% (Cal Hypo)	Chlorine 90% (TCCA / Trichlor)
Active Ingredient	Calcium Hypochlorite (Ca(OCl)₂)	Trichloroisocyanuric Acid (C₃Cl₃N₃O₃)
Available Chlorine	65%	90%
Stabiliser Content	None – unstabilised	Contains cyanuric acid (stabiliser)
Primary Purpose	Sanitisation and shock treatment	Continuous slow-release disinfection
Effect on Calcium Hardness	Raises calcium hardness	Does not add calcium
pH of Solution	Alkaline (~10.8)	Acidic (~2.8)
Mixing Compatibility	DO NOT mix with Trichlor	DO NOT mix with Cal Hypo

Cross-Selling Recommendations

• Stabiliser (Cyanuric Acid)
  For outdoor pools in Kenya’s high-UV climate, adding cyanuric acid stabiliser is recommended to reduce chlorine degradation. This extends the life of free chlorine in the water and reduces overall chlorine consumption.
• pH Plus (Sodium Carbonate)
  Because Chlorine 65% solution is alkaline (~pH 10.8), pH adjustment is often required after dosing. pH Plus raises pH if it has dropped too low.
• pH Minus (Sodium Bisulphate)
  If pH rises too high after Chlorine 65% application, pH Minus brings it back into the optimal 7.2–7.6 range.
• Algaecide
  While Chlorine 65% kills algae, an algaecide provides additional prevention, particularly during Kenya’s warm, rainy seasons when algae growth is most active.
• Flocculant
  For severely cloudy water, a flocculant can be used after shock treatment to coagulate and settle dead algae and debris, accelerating water clarity.

FAQs- Chlorine 65%

1. What is Chlorine 65% used for in swimming pools?
   Chlorine 65% is a calcium hypochlorite sanitiser used for primary pool disinfection and shock treatment, killing bacteria, viruses, and algae.
2. How much Chlorine 65% should I add to my pool?
   Maintenance dosage is 70–100 g per 10,000 litres daily; shock treatment requires 150–200 g per 10,000 litres. Always test water and follow label instructions.
3. Can I mix Chlorine 65% with other chlorine products?
   Never mix Chlorine 65% with Trichlor (TCCA) — this causes violent exothermic reactions, fire, or explosion.
4. Does Chlorine 65% contain cyanuric acid?
   Chlorine 65% is unstabilised and does not add cyanuric acid to pool water. For outdoor pools, add stabiliser separately.
5. Is Chlorine 65% suitable for residential pools?
   Chlorine 65% is suitable for residential pools when handled correctly.
6. Why does Chlorine 65% raise calcium hardness?
   Calcium Hypochlorite releases calcium ions (Ca²⁺) when dissolved, which increases calcium hardness over time.
7. How should I store Chlorine 65%?
   Store in a cool, dry, well-ventilated area below 30°C, away from sunlight, flammable materials, and other pool chemicals.

Summary / Conclusion

Chlorine 65% is a granular calcium hypochlorite swimming pool sanitiser and shock treatment containing 65% available chlorine. It provides primary disinfection by releasing hypochlorous acid to kill bacteria, viruses, and algae. Suitable for both commercial and residential pools, it is cost-effective for large volumes and does not add cyanuric acid to pool water. For outdoor pools in Kenya’s high-UV climate, the addition of cyanuric acid stabiliser is recommended to protect chlorine from UV degradation. Always pre-dissolve before adding, never mix with Trichlor, and store in a cool, dry place.

Need Chlorine 65% 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 3, 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 3, 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 3, 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 3, 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 3, 2026
6. Publisher Source:PubChem (National Library of Medicine)
   Article Title: Calcium Hypochlorite – Compound Summary
   URL: https://pubchem.ncbi.nlm.nih.gov/compound/Calcium-hypochlorite
   Access Date: August 3, 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 3, 2026

 

Chlorine 65%

Chlorine 65% is a granular calcium hypochlorite pool sanitiser and shock treatment containing 65% available chlorine. It kills bacteria, viruses, and algae through the release of hypochlorous acid. Ideal for commercial pools, hotels, schools, and residential pools. Cost-effective, widely available, and does not add cyanuric acid. Important: Pre-dissolve before adding, never mix with Trichlor, and store in a cool, dry place. Available in 1 kg, 5 kg, 20 kg, and 45 kg packaging.

Verified Chemical Technical Specifications

Specification	Detail
Product Name	Chlorine 65%
Generic Chemical Name	Calcium Hypochlorite
Chemical Formula	Ca(OCl)₂
Active Ingredient	Calcium Hypochlorite (Ca(OCl)₂)
Typical Strength / Concentration	65% available chlorine (w/w)
Chemical Family	Inorganic Hypochlorite Salt
Physical Form	Granular or tablet/prill solid
Colour / Appearance	White to off-white granules or pellets; slight chlorine odour
Packaging Sizes	1 kg; 5 kg; 20 kg; 45 kg
Shelf Life	2 years when stored correctly in sealed, dry containers
UN Classification	Class 5.1 oxidising solid

To order contact us now:

• 📞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

 

Meta Description

Buy Chlorine 65% calcium hypochlorite pool sanitiser in Kenya. Granular pool chlorine for disinfection & shock treatment. Available 1kg-45kg. Call Vinsol Kenya +254 715 01 45 10.