Why is My Hot Tub Water Green?

Green water is often caused by algae growth, which happens when sanitizer levels are too low. Shock the water, balance the chemicals, and clean the filters.

What Causes Green Hot Tub Water?

Several factors can cause your hot tub water to turn green. The most common culprits include:

• Algae Growth: Algae spores can enter your hot tub through wind, rain, or contaminated swimwear. Poor sanitation or improper water balance encourages their growth.

• Metals in the Water: Copper, iron, or manganese can oxidize in your hot tub, turning the water green.

• Low Sanitizer Levels: Chlorine or bromine levels that are too low allow bacteria and algae to grow.

• Unbalanced pH Levels: High pH can reduce the effectiveness of sanitizers, making it easier for algae and metals to thrive.

How to Fix Green Hot Tub Water

Here are steps you can take to restore your hot tub’s clear water:

1. Test the Water

• Use a reliable test kit or test strips to measure pH, alkalinity, and sanitizer levels. This will help identify imbalances.

2. Shock the Hot Tub

• Add a strong chlorine or non-chlorine shock treatment to kill bacteria and algae. Follow the product instructions for the right dosage.

3. Clean the Filters

• Dirty filters can trap algae and contaminants. Rinse or soak your filters in a filter cleaner for deep cleaning.

4. Balance the pH and Alkalinity

• Aim for a pH level between 7.2-7.6 and total alkalinity between 80-120 ppm.

5. Add a Metal Sequestrant

• If metals are the cause, a metal sequestrant can help neutralize them and prevent discoloration.

6. Run the Jets

• Circulate the treated water for several hours to ensure chemicals are evenly distributed.

Preventing Green Water in the Future

To avoid green water issues, consider these tips:

• Test Water Weekly: Regular testing ensures your pH, alkalinity, and sanitizer levels are balanced.

• Shower Before Entering: Rinsing off body oils, lotions, and hair products can reduce contamination.

• Rinse Swimwear: Wash swimwear that’s been in lakes, rivers, or oceans to prevent introducing algae spores.

• Clean Filters Regularly: Rinse filters every 2-4 weeks and deep clean them monthly.

• Shock After Heavy Use: Shocking your hot tub after parties or frequent use prevents bacteria buildup.

Why Does My Hot Tub Water Stay Green After Treatment?

If your water remains green despite treatment, consider these factors:

• Filters May Be Clogged: If your filters are dirty, they may need replacement.

• Metals Are Still Present: Adding a metal sequestrant or using a pre-filter when filling the tub may help.

• Algae Hasn't Fully Died: Repeat the shock treatment and brush the interior surfaces to remove stubborn algae.

Is Green Hot Tub Water Safe to Use?

Green water may not always be harmful, but it's best to avoid soaking until the water is clear. Bacteria can thrive in poorly maintained water, posing health risks.

When to Drain and Refill

If your water stays green after multiple treatments, draining and refilling may be the best option. Clean the hot tub shell, jets, and filters before adding fresh water to prevent lingering contaminants.

Keeping Your Hot Tub Clean Year-Round

With proper maintenance, you can enjoy clean, clear water throughout the year. Regular testing, balanced chemicals, and clean filters are key to keeping green water away.