Water chemistry is the core of pool maintenance. Get it right, and your pool stays clear and safe with minimal effort. Get it wrong, and you’ll be fighting algae, irritated swimmers, and damaged equipment – often while adding more chemicals that make things worse.
The five numbers that matter most are pH, free chlorine, total alkalinity, cyanuric acid (CYA), and calcium hardness. They interact with each other – which is why the order you adjust them matters. This section covers all of them in depth, plus specific guidance for saltwater pools.
Quick Reference: Target Ranges
| pH | 7.2 – 7.6 |
| Free Chlorine | 2 – 4 ppm |
| Total Alkalinity | 80 – 120 ppm |
| Cyanuric Acid (CYA) | 30 – 60 ppm |
| Calcium Hardness | 200 – 400 ppm |
Adjust in this order: alkalinity → pH → chlorine. Test weekly.
Pages in This Section
Understanding pH, Alkalinity, and Calcium
The three most interconnected parameters in pool chemistry. Learn what each one does, why they influence each other, and how to adjust them without creating a chain reaction.
How to Test Your Pool Water
A guide to test kits vs. test strips vs. digital testers – what each measures, how accurate they are, and the right testing routine so you’re never flying blind.
How to Balance Your Pool Water
Step-by-step instructions for getting all your chemistry parameters into their target ranges, including what order to make adjustments and how long to wait between them.
Chlorine Guide: Types, Dosing, and Stabilizer
Everything about chlorine: liquid vs. tabs vs. granular, how UV destroys chlorine, why liquid chlorine is the best everyday choice, and how to shock properly.
How to Lower Cyanuric Acid (CYA)
CYA only leaves your pool through water dilution – there’s no chemical fix. This guide covers when CYA is too high, how much water to drain, and how to prevent it from climbing again.
Saltwater Pool Chemistry
Salt pools have the same chemistry needs as chlorine pools, plus salt levels to manage. This guide covers the differences, what the salt cell does to pH, and the complete parameter checklist for salt pool owners.