"Heavy rain dilutes pool chemicals, especially salt and chlorine, which causes the pool to turn green. This means the water is not sanitised or healthy, so it's vital to address this.
The fastest way to clean a green pool is by using pool chemicals and your pool filter. This process usually takes around 4-5 days but you will start noticing a major improvement after 24 hours.
The most common reason pool water turns green is due to algae growing in the water. Algae can grow rapidly, particularly in hot weather, which is why it can surprise you overnight during the warmer months. This generally comes down to an imbalance or lack of chlorine in the water.
Rainwater itself does not cause algae, but it can provide the right environment for algae. Rain will bring phosphates, nitrates and other organic contaminants into the pool. As we discussed earlier, rain also reduces chlorine levels.
When the levels are properly balanced, chlorine will keep the algae at bay, but the water will slowly begin to turn green as the algae take over if there's not enough. But be careful—adding too much chlorine in pool water can cause those metals to oxidize and turn the pool a different shade of green.
What's important for you to know: You shouldn't swim in a pool that's green until you test the chemical levels, like the officials in Rio did before the diving event began. It's the balance of things like chlorine, pH, and alkalinity in a pool that keeps it sterilized.
Should the green be due to pollen, there may be little to do in the way of minimizing the discoloration short of erecting a building around the pool. Fortunately, assuming there are no allergies to the pollen, it is safe to swim in a pool with that as the cause for green water.
Baking Soda and Green, Blue, or Yellow Algae
You'll need to use an algaecide to kill the algae and superchlorinate your pool to clear the water. After this treatment, test your pH and alkalinity and add baking soda to raise alkalinity to at least 100 ppm and pH to between 7.2 and 7.8.
The pool turned green from copper, not algae
Think of the Statue of Liberty. It is made of copper, and has turned green over time through oxidation.
Remember that shocking alone does not clear up a green or cloudy pool; that is what the filter is for. It doesn't matter how much shock you put in the pool if you have a bad filter.
Pool water turns green because of algae in the water. Algae can grow rapidly, particularly when it's warm like Summer, which is why it can surprise you overnight. This generally comes down to an imbalance or lack of chlorine in the water.
High doses of chlorine usually quickly kill the algae and the process can be accelerated by the addition of a good algaecide—to make your customer happier, faster. Once you have treated the pool to kill the algae, your pump and filter have the burden of clearing your water.
If there's not enough chlorine, your pool can turn green. pH Value too high. - pH is a measure of how acidic or basic the water is. A number of different factors can contribute to a high pH level in a swimming pool.
Pools can immediately turn green after shocking when they have metals like copper in the water. These metals oxidise when exposed to high levels of chlorine which makes the pool water turn green. Adding a metal control product such as Zodiac Metal Remover will help to restore the pool water.
Low flow = poor circulation which will lead to algae in the pool. Bottom line, the filter must be backwashed on a regular basis to ensure that your pool water is clear. "When do we need to backwash?" - It is recommended to backwash your filter once every 4-6 weeks of regular use.
Just like you run vinegar through your coffee pot to get rid of calcium buildup, white vinegar can wipe away this eyesore in your pool. Mix a 50/50 solution of vinegar and water, dip a sponge or soft cloth into it, and scrub that residue away.
Clorox itself recommends using between 100 and 200 ounces of regular-strength bleach per 10,000 gallons of pool water -- one gallon is 128 ounces, and many bottles of bleach are available in one-gallon or half-gallon sizes. Pool professionals tend to recommend more conservative amounts of bleach.
It is important to know what exactly bleach is before you put it in your pool. Household bleach, Clorox and liquid chlorine can all be used to sanitize a pool. They are all types of chlorine. Household bleaches such as Clorox usually contain about 5-6% available chlorine, about half that of pool liquid chlorine.