Over the years, I’ve worked with countless spa owners dealing with cloudy water, foaming, odors or even skin irritation. While these issues can seem unrelated, they often trace back to the same cause: contamination in the plumbing.
I’ve seen seasoned spa owners who never had water care issues suddenly struggle to keep their new spa clear. Same house, same source water, same routine — yet the water constantly goes cloudy. Sometimes the problem isn’t how the spa is used, but what’s already inside it when it arrives. I’ve also worked with longtime spa users who enjoyed problem-free water for years, only to have it turn cloudy every few days without explanation. What’s working against them?
You’d be surprised how often a brand-new spa arrives with bacteria, algae, fungus, biofilm or mold already in the lines. At the factory, spas are filled with water for testing, then drained, wrapped, warehoused and shipped. The damp, dark plumbing — with no airflow — is the perfect breeding ground for contaminants. Once the spa is refilled in a backyard, those contaminants flourish and quickly affect water quality.
Contamination can also develop in existing spas. It may come from a garden hose with mold inside, bird droppings or leaves floating in the water, a waterlogged spa cover dripping into the tub, sanitizer levels left too low for too long or even an empty spa left damp for just a few days. (If you have ever left a damp, empty cooler outside in the sun for a day or two, only to find it covered in mold when you open it, you’ll understand what can go on in the plumbing of an empty spa.)
Whatever the source, the signs are the same: persistently cloudy water, scum, foaming, flakes, fizzing, an inability to hold sanitizer, unpleasant odors and sometimes even bather rashes.
When these symptoms appear, the solution is simple: decontaminate.
How to decontaminate a spa
1. Leave the headrests and filter in place.
2. Add chlorine at a ratio of 5 tablespoons per 100 gallons of water.
3. Circulate the chlorinated water through the entire plumbing system.
Run jets, valves, waterfalls, water features, aerators and set diverters midway. If the spa has a floor drain, bleed some of the chlorinated water through it at the start — drains are a dead end where contaminants thrive.
4. Check free chlorine after 24, 48 and 72 hours.
If the level is anything less than extremely high at any point, dose the water again and restart the 72-hour clock. Do not use the spa during this process.
5. After 72 continuous hours of successful chlorination:
- Remove and clean the filter.
- Use a plumbing purge product.
- Drain the spa.
- Install the clean filter and refill according to manufacturer directions.
The troubleshooter’s bottom line
If clients are struggling with cloudy water, foaming, odors or sanitizer that won’t hold, have them decontaminate first. In most cases, it solves the problem. If it doesn’t, at least you know contamination isn’t the culprit — making the next step in troubleshooting easier.