Pool Chemicals Guide: From Green to Clean

Pool Chemicals Guide: How to Turn a Green Pool Crystal Clear

Every pool owner dreams of crystal-clear water and endless hours of summer fun. So, what do you do when you look outside to see your pool has clouded over or turned an alarming shade of green? First, don’t panic—it’s possible to clear a cloudy or green pool with the right chemicals, a few smart steps, and a little patience. Follow this step-by-step guide to remove algae from your pool and get the water looking sparkling clean again.

What Turns Pool Water Green?

Algae is usually the culprit. These microscopic organisms grow fast when your pool’s chemical balance is off, particularly when chlorine drops below 1 ppm and pH levels rise above 7.8. Warm temperatures speed up the process, so be on your guard when summer weather hits. Here are some factors that allow green algae to take over:

• Heavy rain: All that fresh water throws off your pool chemistry. Runoff contributes organic material that promotes algal growth.
• Sunlight: Long, hot days speed up algae reproduction.
• Poor circulation: When water sits still, it becomes the perfect algae breeding ground.
• Neglected maintenance: If you fail to test, clean, or add chemicals regularly, algae may accept the invitation to move in.
• High copper levels: Not all green pools are because of algae. Oxidized copper ions, courtesy of your plumbing or pool equipment, can also tint the water green.

How to Clear a Green Pool

With the right approach, you can evict algae from your pool and restore that clear, inviting blue. Here’s a proven step-by-step method:

1. Brush Every Pool Surface

Algae doesn’t just float around—it also likes to stick to walls, ladders, steps, and other surfaces. Start by brushing every inch of your pool. Focus on spots with visible growth, loosening algae to make it easier for chemicals to kill. Use a nylon bristle brush for fiberglass or vinyl pools and a stainless steel one for concrete.

2. Vacuum the Pool

After brushing, manually vacuum the pool to waste. This bypasses the filter and sends the dirty water straight out of the pool, usually through a backwash or waste line. Vacuuming to waste is ideal to avoid clogging up the filter. If your pool doesn’t have a waste setting, clean the filter often while vacuuming so it doesn’t get overwhelmed.

3. Balance the Water Chemistry

Before adding any chemicals, test the pH and alkalinity. The pH should be 7.2 to 7.6, and the alkalinity should be 80 to 120 ppm. If the pH is too high, chlorine becomes less effective. Lower it with muriatic acid or sodium bisulfate before moving on to the next step.

4. Shock the Pool

Adding pool shock chemicals is the fastest way to kill algae. You’ll need to go beyond a standard dose to create a full-scale attack. Double or triple shock the pool, depending on how dark green it is. Use a calcium hypochlorite shock product, and wear gloves and goggles when handling it. Pour it into the deep end and run the pump continuously for 24 to 48 hours. For the best results, shock the pool at dusk so the sun doesn’t burn off the chlorine before it starts working.

5. Use Algaecide and Clarifier

After shocking the pool, apply algaecide as a preventative measure against regrowth. Choose a product specific to green algae and follow the dosage instructions. A clarifier is also vital for clumping tiny algae particles together. Once clumped, they’re easier for the filter to remove.

6. Repeat if Necessary

The average algae bloom takes four to five days to completely clear. If your pool is still cloudy or slightly green after this time goes by, repeat the steps above. Sometimes, it takes a couple of attempts to fully clear a green pool.

Why Is My Pool Still Green?

If the water is still green after two rounds of pool water balancing, try these troubleshooting tips:

• Double-check which type of algaecide you’re using. Some products are specifically made for green, yellow, or black algae.
• Use a phosphate remover along with your shock treatment to remove excess phosphates that are feeding the algae.
• Clean or replace your cartridge filter.
• Use a metal sequestrant if oxidized copper, not algae, is the culprit behind your green water.

Schedule Pool Services in Orland Park

If you think you’ve done everything right and still can’t fix your cloudy or green pool, call All Seasons Pools & Spas for professional pool cleaning in the Chicagoland area. We’re a family-owned business with an award-winning service team that knows how to take your pool from green and murky to sparkling clean. Our Orland Park store offers free computerized water testing—just bring a sample, and we’ll tell you exactly what your pool needs. We also offer cleaning packages that guarantee your pool will be algae-free by the time we’re finished. Contact us today to schedule a service estimate.