Hot Tub Maintenance 101: A Beginner's Guide to Crystal-Clear Water
Crystal-clear hot tub water comes down to three habits: keep a sanitizer working, keep the water balanced, and keep the filters clean. Test with strips a few times a week, adjust only what's out of range, rinse filters monthly, and drain and refill on schedule. Most owners spend just minutes a week on it.
If you just bought your first Hot Spring® hot tub, or you're about to, this guide covers the basics in plain language. It draws on Hot Spring® Spas' own hot tub water treatment guide. New to spas? Start with our Hot Spring Spas Hot Tubs 101 overview.
What Are the Three Keys to Clear Hot Tub Water?
The three keys to clear hot tub water are a working sanitizer, balanced water chemistry and clean filters. Untreated spa water grows bacteria quickly, and minerals can leave scale on the shell and equipment.
Sanitize
Sanitizer kills bacteria and breaks down contaminants. Compare our hot tub water care systems.
Balance
Keeping pH, alkalinity and hardness in range protects equipment and lets sanitizer work. See our water care instructions.
Choosing a sanitizer system
| System | How it works | Owner effort |
|---|---|---|
| FreshWater® Salt System | Generates chlorine automatically from a low level of salt | Lowest; water can last up to a year with normal use and proper care |
| FreshWater® IQ + Salt System | Adds hourly automatic water testing with clear adjustment prompts | Lowest; available on 2024+ Highlife® and Limelight® models |
| FreshWater® Ozone System | Ozone and silver ions clean constantly; you add chlorine weekly | Low to moderate |
| Manual chlorine | You add chlorine by hand and test often | Highest |
What Should Hot Tub Chemical Levels Be?
Most hot tubs should have free chlorine of 3–5 ppm, pH of 7.2–7.8 and total alkalinity of 80–120 ppm. Test strips show in seconds whether anything needs attention.
| Reading | Typical target | If it's low | If it's high |
|---|---|---|---|
| Free chlorine | 3–5 ppm | Add chlorinating granules | Leave the cover open and let it drop before soaking |
| pH | 7.2–7.8 | Add pH/Alkalinity Up | Add pH/Alkalinity Down |
| Total alkalinity | 80–120 ppm | Add pH/Alkalinity Up | Add pH/Alkalinity Down |
| Calcium hardness | Keep it low; ask us for your model's range | Rarely an issue | Use a calcium remover such as Vanishing Act® |
| Salt (salt systems only) | Per your FreshWater® Salt System setup guide | Add spa salt | Partially drain and refill |
Ranges vary by water care system, so your Hot Spring owner's manual has the final word. Hot Spring notes that 2.0 ppm is the minimum chlorine level ANSI recommends for hot tubs.
Hot Spring uses four kinds of test strips: 5-Way strips for chlorine, bromine, pH, alkalinity and hardness; MPS strips for non-chlorine shock; salt strips; and phosphate strips for salt system owners. Find them all with our Hot Spring spa care products.
How Often Should You Maintain a Hot Tub?
Test hot tub water 2–3 times a week, shock it weekly, rinse filters monthly, and drain and refill every 3–4 months, or up to once a year with a FreshWater® Salt System.
| How often | Task |
|---|---|
| Before each soak | Rinse off in the shower to keep lotions and soap out of the water |
| 2–3 times a week | Test with strips; adjust anything out of range |
| Weekly | Shock with an MPS non-chlorine oxidizer, or add chlorine if you have an ozone system |
| Monthly | Rinse filters with a garden hose |
| Every drain and refill | Soak filters in filter cleaner; wipe down the shell |
| Every 3–4 months | Drain and refill (manual chlorine or ozone systems) |
| Up to once a year | Drain and refill (FreshWater® Salt System with normal use) |
Hot Spring filters can also be cleaned in the dishwasher on an unheated cycle with no soap. For a quick clean between deep cleans, a spray-on, no-soak filter cleaner works well. Shop filters, cleaners and test strips in our online e-store, and keep our hot tub owner's guide handy.
Starting fresh after a refill
The water that goes in matters as much as the care that follows. Hot Spring recommends fill water that is free of metals like iron, copper and manganese, and low in calcium. Bring a tap water sample to our Dayton showroom for a test. A hose pre-filter or portable softener may be all you need.
How Do You Fix Cloudy, Foamy or Smelly Hot Tub Water?
Cloudy, foamy or smelly hot tub water usually comes from low sanitizer, unbalanced pH, a dirty filter or soap residue. Match your problem to the fix below.
| Problem | Likely cause | Fix |
|---|---|---|
| Cloudy water | Low sanitizer, high pH or a dirty filter | Test and rebalance, shock the water, then rinse or replace the filter |
| Foam on the surface | Soap, lotion or detergent residue from bathers or swimsuits | Rinse before soaking; if it persists, drain and refill |
| Strong chemical smell | Used-up sanitizer, not too much of it | Shock with an MPS oxidizer and retest |
| Scale or white residue | High calcium or hard fill water | Use a calcium remover; test tap water before the next fill |
| Green or discolored water | Metals in fill water or very low sanitizer | Use stain and scale control, shock, and call us if it doesn't clear |
Still stuck? Bring a water sample to HotSpring Spas of Dayton for a water analysis, or request hot tub service online.
Frequently Asked Questions
How often should I test my hot tub water?
Two to three times a week is a good habit for most owners. Smart systems like FreshWater® IQ test automatically every hour and tell you when to adjust.
How often should I drain and refill my hot tub?
Every three to four months for most chlorine and ozone systems. With the FreshWater® Salt System and proper care, water can last up to a year of normal use.
Why is my hot tub water cloudy?
Usually low sanitizer, high pH or a dirty filter. Test the water, rebalance, shock it and clean the filter.
How do I clean hot tub filters?
Rinse them with a garden hose monthly and soak them in filter cleaner at every drain. Hot Spring filters can also go in the dishwasher on an unheated cycle without soap.
What is the easiest hot tub water care system?
A salt water system is the most hands-off. Hot Spring's FreshWater® Salt System generates chlorine automatically, and the FreshWater® IQ add-on monitors the water for you. See the benefits of salt water hot tubs.
Can I use ozone and salt water together?
No. Hot Spring advises against combining an ozone system with a salt water chlorine generator.
Keep Reading
Get Water Care Help From HotSpring Spas of Dayton
Clear water shouldn't be a chore. HotSpring Spas of Dayton has helped local spa owners since 1981. Our team can test your water, recommend the right products for your spa and set you up with a FreshWater® Salt System for the most hands-off care. See what our customers say in our reviews.
Mon–Fri: 10 AM–8 PM
Sat: 10 AM–6 PM
Sun: 12–5 PM
Source: Hot Spring® Spas, The Ultimate Hot Tub Water Treatment Guide. Chlorine, pH and alkalinity ranges are common industry targets; confirm against your owner's manual.