💧 Why Did My Pool Water Turn Brown or Green After Adding Chlorine? - Water Coloration / Oxidation in Pools

A clear, honest guide for Bestway® pool owners in Indian conditions

You finally do the “right thing.” You test the water, add chlorine carefully, switch on the pump… and a day later your pool looks worse, not better. The water turns light green, tea-brown, or sometimes a murky yellowish shade.

Naturally, the first reaction is panic: “Did chlorine spoil my pool?” “Is my liner damaged?” “Is this algae exploding?”

Take a deep breath. In most Indian homes, chlorine is not the problem—it’s actually doing its job a little too well.

Let’s break this down calmly and clearly.

🌿 The Short Answer (In Simple Words)

When you add chlorine to pool water that contains iron, manganese, copper, organic matter, or very high TDS, chlorine oxidizes these invisible substances.

Once oxidized, they change colour and become visible:

• Iron → brown / tea-colour

• Manganese → dark brown / blackish tint

• Copper → green / turquoise

• Organic load (dust, leaves, sweat) → cloudy green

So the colour change is actually proof that chlorine is working, not failing.

🔬 What Exactly Is Happening Inside the Water?

1️⃣ Chlorine Is an Oxidizer, Not Just a Germ Killer

Most people think chlorine only kills bacteria and algae.In reality, chlorine is a powerful oxidizer.

That means it reacts with:

• Dissolved metals (iron, manganese, copper)

• Organic contamination (soil dust, pollen, sweat, oils)

• Old ammonia-based compounds

Before chlorination, these substances are invisible. After oxidation, they precipitate or suspend in water—creating colour.

🟤 Brown Water After Chlorine — The Iron Story

Where does iron come from?

Very common Indian sources:

• Borewell / groundwater

• Old GI pipelines

• Tanker water

• Rooftop storage tanks with rust

What happens after chlorine?

• Dissolved iron (Fe²⁺) → oxidized iron (Fe³⁺)

• Oxidized iron becomes brown/yellow particles

• These either float or settle on liner seams and floor

Important note:

This is not algae. Brushing won’t fix it. More chlorine may make it darker.

🟢 Green Water After Chlorine — Two Different Scenarios

Scenario A: Copper Reaction (Common with Borewell Water)

• Copper comes from:

  • Borewell water

  • Certain plumbing fittings

  • Low pH water dissolving metals

• Chlorine oxidizes copper → green or turquoise tint

• Water may stay clear but look green

Scenario B: Algae + Low Chlorine Reserve

• Chlorine added, but:

  • pH is too high

  • TDS is very high

  • Organic load is excessive

• Chlorine gets consumed instantly

• Algae partially dies → water turns dull green or cloudy

🧪 Why This Happens More Often in Bestway Pools (And That’s OK)

Bestway pools are:

• Above ground

• Lined with smooth PVC

• Filled directly from municipal / borewell sources

Unlike RCC pools (which hide problems in plaster pores), Bestway pools show water chemistry honestly.

If your source water has metals or high TDS, the pool reveals it quickly—especially after the first chlorine dose.

This is actually a good diagnostic sign, not a defect.

📊 Quick Diagnosis Table

Water Colour	Appears After	Most Likely Cause
Tea brown / yellow	6–24 hours	Iron oxidation
Dark brown specks	Immediately	High iron or manganese
Clear but green	Same day	Copper oxidation
Cloudy green	1–2 days	Algae + poor filtration
Grey / dull	Few days	High TDS & dead organics

🛠️ What You Should Do (Step-by-Step)

✅ Step 1: Do NOT Panic-Chlorinate

Adding more chlorine without diagnosis can:

• Darken metal stains

• Increase TDS

• Stress the liner

✅ Step 2: Run Filtration Continuously (12–24 hrs)

• Oxidized particles need time to circulate

• Backwash / clean cartridge after colour stabilizes

✅ Step 3: Balance pH First

• Ideal pH: 7.4 – 7.6

• High pH locks metals in suspension

• Correct pH improves filtration capture

✅ Step 4: Use a Metal Control / Sequestrant

Especially if you use:

• Borewell water

• Tanker water

• Old pipelines

Metal control binds oxidized metals so the filter can remove them instead of staining the liner.

✅ Step 5: Partial Drain & Refill (If Needed)

If:

• TDS is very high

• Iron keeps reappearing

• Water stays brown despite filtration

A 20–30% drain and refill with better-quality water works wonders.

🚫 What NOT to Do

❌ Do not scrub brown stains aggressively

❌ Do not use powdered chlorine directly on liner

❌ Do not mix multiple chemical brands blindly

❌ Do not ignore pH and alkalinity

These mistakes shorten liner life and worsen staining.

APX365 Pool with Maintained Borewell Water

🧴 Our Recommended Chemical Philosophy (Important)

At Bestway Gujarat, we strongly recommend:

• Liquid chlorine only

• Liquid algaecide only

Why?

• Powders and tablets can sit on the liner

• High local concentration causes bleaching or pinholes

• Liquid disperses evenly and reacts predictably

Dosage and frequency must always be based on:

• Product concentration

• Pool volume

• Local water quality

🧑‍🔧 When Additional Help May Be Required

If you notice any of the following even after following the diagnostic steps above:

• Persistent brown or yellow stains forming on the liner

• Green or brown water that does not improve after 48 hours of proper filtration

• Repeated colour change every time chlorine is added

These situations usually indicate ongoing metal contamination, very high TDS, or source-water issues that require deeper intervention beyond routine pool care.

Support Availability (Important to Note)

• Paid technical support (call, WhatsApp, or on-site) is available only to customers who have purchased their pool from Bestway Gujarat, subject to service scope and availability.

• This support is meant for structured diagnosis and corrective action, not emergency or free troubleshooting.

We are also developing structured video-based pool care courses (Hindi & English) covering water chemistry, filtration logic, and seasonal maintenance. These courses will be available for purchase separately and can be used by homeowners, caretakers, and hospitality staff alike.

For Bestway Gujarat Customers

Eligible customers may be asked to share:

• Clear photos or short videos of the pool water

• Source of water used (municipal / borewell / tanker)

• Pool model and approximate water volume

📲 WhatsApp +91-96645-22268 (availability subject to service terms)

This ensures the diagnosis is accurate, repeatable, and based on data—not guesswork.

🌊 Final Thought

When pool water turns brown or green after adding chlorine, it’s not a failure—it’s a revelation. Chlorine is exposing what was already hiding in your water.

Understand the chemistry, respond calmly, and your Bestway pool will reward you with clear, safe, inviting water—season after season.

Live it up with Bestway.