If you’ve ever glanced at your backyard and noticed your pool has turned from crystal blue to murky green, you’re not alone. Florida’s humidity, high temperatures, and sudden rainstorms can quickly throw off your pool’s chemistry. At Legion Pools, we’ve helped countless St. Petersburg homeowners reclaim their sparkling waters—and we’re here to walk you through how to fix a green pool the right way.
Whether it’s a light tint or a full-on swamp situation, here’s what you need to do:
Step 1: Assess the Shade of Green
Not all green pools are the same. The deeper the green, the more advanced the algae growth. A light green tint usually means early-stage algae, while a dark or murky green pool likely has multiple imbalances and bacterial growth.
Legion Tip: Snap a photo and compare it to previous days to monitor how fast the algae is spreading. If it’s worsening quickly, act fast to prevent damage to your pool surfaces.
Step 2: Test Your Water Chemistry
Before dumping in chemicals, test your pool’s pH, chlorine, and alkalinity levels using a reliable kit or bring a sample to your local pool store. Chances are, your chlorine is dangerously low, and your pH is off-balance—both conditions algae love.
Goal Ranges:
- Chlorine: 1–3 ppm (likely near 0 if your pool is green)
- pH: 7.2–7.6
- Alkalinity: 80–120 ppm
Step 3: Shock the Pool—Heavily
Shocking means adding a high dose of chlorine to kill off algae and bacteria. If your pool is dark green, you’ll likely need multiple rounds of shock treatment. Follow the manufacturer’s instructions based on your pool size.
Legion Tip: Use calcium hypochlorite shock and do it in the evening to prevent the sun from burning off the chlorine too quickly.
Suggested Dose:
Light green pool: 1–2 lbs per 10,000 gallons
Dark green pool: 3–5 lbs per 10,000 gallons
Step 4: Brush, Brush, Brush
Once the shock starts working, brush all surfaces—walls, steps, and floors—to dislodge algae clinging to the surfaces. This helps the chlorine reach every nook and cranny.
Don’t skip this step—it’s one of the most critical parts of pool recovery.
Step 5: Run the Pump and Filter Nonstop
Keep your pump and filter running 24/7 for at least 48–72 hours after shocking. You’ll need constant circulation to remove dead algae and clean up the water. Backwash your filter regularly to keep it working efficiently.
Bonus: Consider using a flocculant or clarifier to help particles settle and speed up the cleaning process.
Step 6: Vacuum Out Debris
After a day or two of circulation, vacuum the settled debris and algae from the bottom of the pool. If there’s too much gunk to vacuum to your filter, use the “waste” setting to bypass the filter entirely.
Step 7: Re-Test and Balance
Once your pool is mostly clear, retest your water and adjust chemicals as needed. Balance your chlorine, pH, and alkalinity levels to prevent a repeat outbreak.
Bonus: Prevent Green Pool Comebacks
At Legion Pools, we believe prevention is just as important as treatment. Here’s how to avoid future green pool disasters in St. Petersburg:
- Maintain chlorine levels weekly
- Clean skimmer baskets and filters
- Shock the pool after heavy rain or heavy usage
- Trim trees and bushes to reduce organic debris
Don’t Want to Do It Alone?
Fixing a green pool can be labor-intensive and time-sensitive. If you’d rather leave it to the pros, Legion Pools offers fast, reliable green pool clean-up services in the greater St. Pete area. We’ll test, treat, and restore your pool so you can get back to enjoying it—without the stress.
👉 Contact Legion Pools today for expert green pool recovery and maintenance services.