Can You Fill a Pool with Well Water? What to Know

Before You Fill

Check Your Well Capacity

• Average pool: 15,000-30,000 gallons
• Small pool (under 15,000): 1-2 days filling
• Large pool (30,000+): 2-4 days
• Can your well produce this without issues?

Flow Rate Matters

Don't Pump Continuously

• Running pump non-stop can overheat
• Can outpace well recovery
• Fill in stages if low-yield well
• Let well recover between sessions

Know Your Water

• Iron level: crucial for pool
• pH: affects chlorine effectiveness
• Hardness: affects balance
• Test before filling if possible

Common Problems

Iron Staining

• The problem: Add chlorine → water turns green/brown
• Why: Chlorine oxidizes dissolved iron
• Result: Rust color, can stain pool surface
• Prevention: Add metal sequestrant BEFORE chlorine

High Minerals

• Hard water = scale buildup
• Affects pool equipment
• Clouds water
• Hard to balance chemistry

Low pH

• Well water often acidic
• Corrodes equipment
• Burns eyes
• Will need to raise pH

Manganese

• Similar to iron—stains when oxidized
• Black/brown staining
• Treat like iron

Copper

• Can turn hair green
• Blue-green staining
• From acidic water on copper pipes

Filling Tips

Best Practices

1. Test your well water first (iron, pH, hardness)
2. If high iron: consider filtration while filling
3. Fill slowly to not stress well
4. Don't run well dry
5. Monitor water level if low-yield well

Inline Filtration

• Attach filter to hose
• Removes iron as it fills
• Better than treating after
• Various products available

Timing

• Fill overnight when not using house water
• Split over multiple days if needed
• Watch for pump overheating (hour on, hour off)

Treatment After Filling

Step 1: Test

• Test pool water for metals, pH, alkalinity, hardness
• Know what you're dealing with

Step 2: Metal Sequestrant

• Add BEFORE chlorine if iron present
• Keeps metals in solution
• Prevents staining
• Follow product directions

Step 3: Balance Chemistry

• Adjust pH (7.2-7.6)
• Adjust alkalinity (80-120 ppm)
• Address hardness if needed

Step 4: Add Chlorine

• Only after sequestrant has circulated
• Add slowly
• Watch for color change (iron oxidizing)

If Water Turns Green/Brown

1. Add more sequestrant
2. Run filter continuously
3. May need to drain and refill (extreme cases)
4. Consider flocking and vacuuming

Alternatives

Water Delivery

• Trucked water: $200-$500 for 15,000-20,000 gallons
• Often city water (treated, no iron)
• Fast—fills in hours
• No stress on your well

Mix Well and Trucked

• Fill halfway with well water
• Top off with trucked water
• Dilutes minerals
• Saves some money

Fire Department

• Some departments fill pools for a fee
• Call to ask
• Availability varies

When to Use Well Water

• Good well with adequate flow
• Low-iron water
• You're comfortable treating
• Cost savings worth the effort

We service all major pump brands including Franklin Electric, Grundfos, Goulds (Xylem), and Sta-Rite (Pentair). Our trucks carry common parts and components for same-day repairs.

Frequently Asked Questions

Can I fill my pool with well water?

Yes, but be prepared for iron/mineral issues. Pre-treat or use sequestrants. Ensure well can handle the volume.

Why did my pool turn green after filling with well water?

Iron oxidized by chlorine. Use metal sequestrant before adding chlorine. May need to drain if severe.

How long does it take to fill a pool with well water?

Depends on well flow. At 10 GPM, a 20,000-gallon pool takes about 33 hours (1.5 days continuous).

Will well water stain my pool?

Can, if iron or manganese present and not treated. Use sequestrant and filter. Treat before chlorinating.

Should I just pay for water delivery?

Consider it if: low-yield well, high iron, don't want to deal with treatment. Usually $200-$500 for typical pool.