The Ultimate Guide to Indoor Swimming Pool Water Treatment

For those investing in an Origin indoor swimming pool, water quality is paramount. Proper chemical management ensures crystal-clear water, a hygienic environment, and the longevity of your pool’s components. At Origin, we engineer every pool with precision, ensuring the best water management system is chosen from the outset. Here’s everything you need to know about keeping your indoor pool water clean and perfectly balanced year-round.

Indoor pool house

Choosing the Right Dosing System

Your pool’s dosing system should be specified at the design stage to prevent issues down the line. Certain materials, such as the pool cover roller and heat exchanger, require specific treatments to prevent degradation. Without proper planning, corrosive elements in the water can damage your pool infrastructure, leading to costly repairs.

Chemical Treatment Options for Indoor Pools

1. Salt Water Chlorination – Not Ideal for Indoor Use

While salt water chlorination is a popular option for outdoor pools, we generally advise against using it for indoor pools. Here’s why:

  • Corrosive Atmosphere – Salt can create an aggressive environment that, if not controlled by advanced air handling systems, will corrode metal components in the pool hall over time.
  • Hidden Damage Risks – Corrosion doesn’t just affect visible components; concealed fixings and fittings may deteriorate unnoticed, leading to structural integrity concerns.
  • Best for Outdoor Pools – The open air allows the corrosive nature of salt to dissipate naturally, making it much better suited for outdoor pools.
Indoor view of luxury pool house
Close up of pool water
2. Chlorine – Powerful but Demanding

Chlorine remains a reliable choice for sanitizing pools, but it comes in different forms, each with its own considerations:

  • Stabilised Chlorine (Tablets and Granules) – This contains cyanuric acid, which protects chlorine from UV degradation. It’s ideal for outdoor pools exposed to sunlight, but less suitable indoors. Cyanuric acid builds up in indoor pools where there’s no UV to deplete it, potentially reducing chlorine’s effectiveness over time.
  • Liquid Chlorine – This contains no cyanuric acid, making it a better fit for indoor use, particularly in hydrotherapy or commercial settings where rapid response to changes in water conditions is required. However, its liquid form also brings hazards such as potential for spills and vapour release, requiring careful handling and storage.
  • Skin Irritation Risks – Incorrect dosing remains the leading cause of discomfort for swimmers, making precise control essential.
3. Bromine – The Preferred Choice for Indoor Pools

At Origin, bromine is often our recommended solution for indoor pool water treatment:

  • Superior Stability – Bromine maintains its efficacy better in warm water and fluctuating conditions, making it ideal for private indoor pools where usage patterns vary.
  • Gentler on Skin – Less irritating than chlorine, bromine ensures a more comfortable and luxurious swimming experience.
  • Best for Indoor Conditions – Because bromine isn’t affected by UV in the same way as chlorine, there’s no need to manage cyanuric acid levels indoors.
Underwater view of pool
indoor view of bespoke pool
4. High-Temperature Pools & Hydrotherapy – Bromine Comes Out Top

For hydrotherapy pools and hydro spas operating at elevated temperatures, bromine is often the best choice due to its stability in warm water. The Importance of pH Balance Regardless of the sanitization method used, maintaining proper pH is non-negotiable:

  • Enhanced Efficiency – Chlorine and bromine are only effective within optimal pH ranges.
  • Water Clarity – Balanced water should be crystal-clear and visually pristine.
  • No Strong Odours – A well-maintained pool should have minimal detectable chemical smell.

Manual vs. Automatic Dosing Systems

Many pool owners ask whether to go manual or automatic. Automated systems reduce dayto- day maintenance, but we always recommend regular testing, particularly before swimming. The best systems are tailored to your usage, pool volume, and the materials used in its construction. Our team at Origin can help specify the ideal setup to match your lifestyle.

indoor view of pool
external view of pool house
Why Choose Origin Pools?

At Origin, water management is not an afterthought—it’s engineered into every detail. We select only the most suitable systems for your unique pool environment, materials, and usage preferences. Whether you opt for bromine’s stability or chlorine’s reactivity, we ensure everything is designed for effortless performance and minimal stress. You’re not just buying a pool—you’re investing in 40+ years of expertise, world-class engineering, and a commitment to flawless execution. When only the best will do, Origin delivers.

Ready to Design Your Dream Pool?

For personalised advice on water treatment systems and to begin your journey with Origin, speak with our team today. Call us on 01895 823366 or email info@originpools.co.uk - we’ll be happy to guide you through the next steps

External Sources for Additional Reading
  1. Swimming Pool Water Chemistry & Treatment Guidelines
  2. pH Balance & Pool Water Quality
    • NSPF (National Swimming Pool Foundation) - Water Chemistry Basics
      Detailed breakdown of pH levels, sanitization, and water testing.
      Link: https://www.nspf.org
    • Swim England – Pool Water Treatment Advisory Group (PWTAG)
      UK-based authority on pool water treatment, especially for indoor pools.
      Link: https://www.pwtag.org
  3. Air Handling & Indoor Pool Environments
    • ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers)
      Best practices for indoor pool ventilation and air quality.
      Link: https://www.ashrae.org
  4. Chlorine vs Bromine & Alternative Sanitizers
    • EPA (Environmental Protection Agency) – Chlorine & Bromine Regulations
      Health and environmental safety guidelines on pool sanitization.
      Link: https://www.epa.gov
    • NSPF (National Swimming Pool Foundation) - Bromine vs. Chlorine
      Comparative effectiveness of chlorine and bromine in swimming pools.
      Link: https://www.nspf.org
  5. Swimming Pool Materials & Corrosion Resistance
    • Lennox - Effects of Saltwater on HVAC & Indoor Air Quality
      Why saltwater can be corrosive to indoor pool environments.
      Link: https://www.lennox.com

Origin Swmming Pools

Looking to bring your indoor pool vision to life? You’re in the right place. With over 40 years of experience, Origin is an award-winning UK company specialising in bespoke indoor pools.

Get In Touch

Origin Leisure Ltd
Summerhouse Business Park
Harefield
Middlesex
UB9 6TH

01895 823366
info@originpools.co.uk

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