How to Fix Cloudy Spa Water – A Simple Step-by-Step Guide

Cloudy spa water? You’re not alone. It's one of the most common spa problems and can make your spa look dirty and uninviting. Luckily, it’s usually easy to fix.

In this guide, Spa World’s water care experts explain exactly how to clear cloudy spa water step by step, what causes it, and how to prevent it from coming back.

Quick Summary: How to Clear Cloudy Spa Water

1. Test the water – pH, alkalinity, and sanitiser levels
2. Clean or replace the filter
3. Add a shock treatment
4. Use a clarifier (optional but helpful)
5. Run the pump for 4–6 hours
6. Recheck water balance
7. Drain and refill if needed

Let’s walk through each step in detail.

Step 1: Clean or Replace Your Filter

A dirty or clogged filter is one of the biggest causes of cloudy water.

What to do:

• Remove your filter
• Rinse with a hose to remove debris
• Soak in filter cleaner overnight (weekly)
• Replace your filter every 12 months or as recommended

Note: Purezone™ and other Micron filters cannot be cleaned using a hose or cartridge cleaner; they must be replaced with a new filter.

Tip: Spa World recommends rinsing your filter every week and deep cleaning it monthly.

Step 2: Test Your Spa Water

Start by checking your water chemistry. Cloudiness is often caused by imbalanced water, usually:

• Body oils
• High pH or alkalinity
• Low sanitiser (chlorine)
• Excess dissolved solids or contaminants

What to use: Spa water test strips

• A digital water tester

Ideal water balance:

• pH: 7.2 – 7.6
• Alkalinity: 80 – 120 ppm
• Chlorine: 3 – 5 ppm
• Bromine: 4 – 6 ppm (We do not recommend using bromine in your spa)

Step 3: Shock the Water

If the water is cloudy due to contaminants like oils or organic matter, shocking your spa is the fastest way to clear it.

Use:

• Non-chlorine shock, like MPS shock for regular use
• Use a Shock dose of chlorine sanitiser for stubborn cloudiness

Follow the shock product instructions carefully.

Important: Keep your spa cover off for at least 30 minutes after shocking to let gases escape.

Step 4: Add a Clarifier

The particles that make spa water look clear are often smaller than the pores in your spa filter, so they go right through the filter media. Spa water clarifiers bind tiny particles together into particles large enough that your filter can catch them.

When to use a clarifier:

• After shocking, if the water is still cloudy
• If water looks hazy, but your levels are balanced

Clarifiers are safe, natural, and easy to use, and help speed up the clearing process.

Step 5: Run the Pump for 8-10 Hours

For Vortex^® and Fisher^® spas we recommend that the circulation pump operates at least eight hours, which allows the water to circulate through the filter, ozone and UV systems.

• Run the pump and filter for at least 6-8 hours
• If possible, run it continuously until the water clears
• Set your spa to “filter cycle” mode if it has one

Most cloudiness clears within 24 hours with proper circulation.

Step 6: Recheck Water Levels

After 24 hours, test the water again. You may need to:

• Adjust pH or sanitiser again
• Add more shock
• Clean the filter a second time

If the water is still cloudy, go to Step 7.

Step 7: Drain and Refill (If Needed)

Sometimes the best fix is a fresh start.

• Drain and refill your spa if:
• Cloudiness persists after shock and filtration
• Water is older than 3–4 months
• TDS (Total Dissolved Solids) are too high

Spa World recommends draining and refilling your spa every 3–4 months for clean, safe water.

Need Help? Talk to a Spa World Expert

Still have cloudy water? Contact Spa World to speak with a water care specialist for free expert advice. Our team is here to help you enjoy clean, crystal-clear spa water all year round.