You’ve been pulled away from your swimming pool maintenance routine unexpectedly, and when you return, you discover that your water, which is normally crystal clear, is now an icky green. Fortunately, there are actions you can take to correct the problem quickly. Below are seven steps that can have your pool clean and swim-ready in as little as 24 hours.
7 Steps from Green to Clean
- Assess. Before you take any corrective action, you should evaluate the situation. In some instances, a pool may be so green that it almost appears black. Choose the recommended course of action based on what type of pool you have. If you don't know the recommended action, talk with your local dealer for advise.
- Test. Using a high-quality test kit, determine what your pool’s pH level is. A high pH will result in the water being especially cloudy when you shock it in the next step. If the pH is high, add one gallon of the muriatic acid to the pool water (for an average size pool of 12-15,000 gallons). Check the level again and make adjustments as needed after shocking and four hours of continually filtering the water. You also want to adjust the calcium hardness as need to reach 200 - 400 ppm.
- Shock. Once the pH is 7.2 or lower, add a chlorine-based shock following the manufacturer’s instructions. Be aware that an algae-killing shock requires more chemicals than a shock when algae is not present.
- Filter. After ensuring that your filter is clean, run it for 12 to 24 hours, adding an algaecide to the water after a few hours. Check the water again when the cycle is complete, both visually and with a test strip.
- Repeat. If the water is not yet clean, ensure that pH and calcium hardness are at the right levels and shock again. Run the filter for another 12-24 hours.
- Vacuum. When the shock has done its job, vacuum up as much algae and other material as you can.
- Maintain. Keep your pool chemicals at the right levels going forward to prevent a recurrence. This can also help you get more life out of your pool cover, which can be damaged by chemicals that get out of balance.
Ideally, your pool chemicals should never get out of balance and allow algae to get the upper hand. But, of course, life happens. By following the steps above — and with some additional insights from our Pool Care & Maintenance page — you can have your pool back in swim shape in no time.