Chlorine for Spas
Chlorine sanitizes hot tub water by killing bacteria and oxidizing organic waste. Learn why it is needed and how to manage it safely.
Why this chemical is used
Chlorine is the primary sanitizer in many spas. It protects bathers by maintaining a measurable residual in the water.
When it is needed
Free chlorine is the portion available to sanitize. Combined chlorine is used-up chlorine attached to contaminants. If water smells harsh, the issue may be combined chlorine or poor oxidation, not too much free chlorine.
How to use it safely
- Test before adding anything.
- Calculate dose based on actual spa volume.
- Add chemicals separately with circulation running.
- Wait, circulate, and retest before adding more.
- Follow the product label and spa manufacturer instructions.
Small spas are easy to overdose. When unsure, add less, circulate, and retest.
Recommended spa supplies
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Breaks down oils and residue that rinsing alone leaves inside cartridge pleats.
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Oxidizes bather waste after heavy use without turning every cleanup into a chlorine spike.
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A fresh cartridge restores flow when cleaning no longer clears residue or debris.
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