---
title: "What Is Combined chlorine? Pool Glossary | Marina Pool Services"
description: "Combined chlorine is chlorine that has already bonded with sweat, oils, and other waste, so it no longer sanitizes well."
url: https://marinapool.multisites.ai/glossary/combined-chlorine
publisher: Marina Pool Services
phone: +1-817-896-1120
quote: https://marinapool.multisites.ai/contact
---

Water chemistry

# Combined chlorine

Combined chlorine is chlorine that has already bonded with sweat, oils, and other waste, so it no longer sanitizes well.

Combined chlorine is the used-up part of your chlorine. It forms when chlorine reacts with swimmer waste, leaves, and sunscreen. It causes the strong pool smell and red eyes.

Most health departments limit combined chlorine to 0.4 ppm or less, according to CDC. You find it by taking [total chlorine](https://marinapool.multisites.ai/glossary/total-chlorine) and subtracting [free chlorine](https://marinapool.multisites.ai/glossary/free-chlorine). If the number is high, the fix is to raise free chlorine well above it, which is called [breakpoint chlorination](https://marinapool.multisites.ai/glossary/breakpoint-chlorination). Follow the product label.

[Marina can helpPool Maintenance Services](https://marinapool.multisites.ai/our-services/pool-maintenance-services)

## Related terms

-   [Chloramine](https://marinapool.multisites.ai/glossary/chloramine)
-   [Total chlorine](https://marinapool.multisites.ai/glossary/total-chlorine)
-   [Breakpoint chlorination](https://marinapool.multisites.ai/glossary/breakpoint-chlorination)
-   [Shock](https://marinapool.multisites.ai/glossary/shock)

## Sources

1.  [CDC Healthy Swimming: Chloramines and Pool Operation](https://www.cdc.gov/healthy-swimming/toolkit/chloramines-and-pool-operation.html)

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[Call (817) 896-1120](tel:+1-817-896-1120)[Get a quote](https://marinapool.multisites.ai/contact)

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