Not all water is created equal for hot tubs. Learn the pros and cons of tap vs. well water and how to treat each type to protect your spa from scaling, staining, or corrosion.

What Type of Water Should I Use in My Hot Tub? Tap vs. Well Water Explained

Filling your hot tub seems simple—but the water you use can affect everything from jet performance to lifespan. Choosing between tap and well water has real consequences for maintenance and safety. Here’s how to do it right.

Option 1: Tap Water (Municipal)

Tap water is treated and usually safe for direct spa use, but still requires testing and balancing once in the tub.

• Pros: Pre-filtered, typically neutral in pH and mineral content
• Cons: May contain residual chlorine or chloramines; can still be hard in some areas

How to Treat Tap Water:

• Use a pre-filter on your hose to reduce any lingering contaminants or sediment
• Test water immediately after filling to check pH (7.2–7.8) and total alkalinity (80–120 ppm)
• Adjust hardness levels if calcium is too low or high

Option 2: Well Water

Well water is untreated groundwater and often contains high levels of iron, manganese, calcium, or sulfur—leading to staining, odor, and cloudy water if not managed properly.

• Pros: Readily available and free of municipal chemicals
• Cons: High hardness and mineral content; may cause foaming, scaling, or staining

How to Treat Well Water:

• ALWAYS use a hose filter rated for iron and sediment when filling
• Use a metal sequestrant (stain and scale control) immediately after filling
• Shock the spa and balance pH/alkalinity within the first 24 hours
• Flush and clean filters more often, especially in the first week of use

Can I Use Softened Water?

Water softened by a home water softener isn’t ideal. It may be low in calcium, which leads to foaming and possible corrosion of spa components. If needed, mix with regular tap water to maintain balance.

Final Recommendation

• If you have access to clean tap water: use it, test it, treat it
• If using well water: filter it, pre-treat it, and monitor it closely for the first week

With either source, always use test strips and maintain proper chemistry to protect your spa investment.