If your hot tub water is green, it’s likely due to algae growth or metal contamination. To resolve this, start by testing and balancing the water's pH and alkalinity levels. Shock the water with a strong sanitizer to kill any algae. Clean the filter thoroughly, as a dirty filter can exacerbate the issue. If metals are present, use a metal sequestrant to remove them from the water. Regular maintenance, including proper chemical balance and cleaning, can prevent future occurrences. Addressing the issue promptly ensures your hot tub remains clean and safe for use.