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How To Clean Your Pool When The Water Is Green

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Without constant maintenance, your pool's water can start to look a little disgusting. Apart from bugs, leaves and dirt, you may notice that your water is turning green. Depending on when you catch it, it may be anywhere from light green to nearly black. This can happen if you let your pool sit without treatment for even a few days, and is caused by the growth of algae. Luckily it can be fixed much more quickly; in many cases, if the algae grown is not too high, you can clean your water with chemicals instead of having to drain and refill the pool.

1. Measure pH Balance

Before treating your pool, make sure that your pool water is at a certain pH balance. Ideally you'll want it somewhere between 7.2 and 7.8 while you're treating your water. Add acid or base as necessary to bring it to around that level. You can add sodium bicarbonate to increase the pH level or add sodium bisulfate to lower it. After adding the acid or base, run your pumps for a few hours to circulate the water, then test it again. If it isn't right the first time, don't worry; just add more acid or base, circulate the water, then try again.

2. Shock Your Pool

A pool shock uses three to five times more chlorine than usual for the purpose of sanitizing your pool. How powerful a shock you use will depend on how much algae is growing in your pool. You can tell what type of shock to use by what color your pool water is. For example, you may use a double, triple or quadruple shock.

  • Double Shock: A double shock is typically used when your water is light green or teal. To double shock, use two pounds of shock for every 10,000 gallons.
  • Triple Shock: Green or dark green water means you'll need to use a more powerful shock. To triple shock, use three pounds for every 10,000 gallons.
  • Quadruple Shock: Black green water will require an extremely powerful shock; for this one you'll need to use four pounds per 10,000 gallons.

The best time to use a shock is at dusk or after, because any sunlight will reduce the shock's effectiveness. To further ensure that the shock works well, first dissolve it into a bucket of water before adding it to your pool to make sure that it spreads.

Make sure your filtration system is clean, start your filter and then pour the shock in front of a return line fitting. Pour it slowly to make sure it is all carried into the pool, and pour from as close to the surface as you can manage.

After a shock, your water will be cloudy; this is normal, and will go away as the filters continue to run.

Refill Your Pool (Optional)

While heavy algae growth can be treated with a pool shock, that process can get a little expensive depending on how much you need to buy. If it turns out that it would be less expensive to drain and refill your pool, that's a perfectly viable option. Just be sure to keep up with swimming pool maintenance from companies like Shawnee Pools to prevent so much algae growth in the future.