"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.
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.
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.
One of the most common problems you will run into when storing rainwater is the algae growth in water tanks. The presence of algae growth in water tanks will make your harvested water nearly unusable. Algae is a bacteria that can carry toxins that are harmful to animals, humans and plants.
If you suspect swimming pool algae is making your pool water green or cloudy, check the water's alkalinity and pH balance. This is the most common cause of green pool water. Unfortunately, algae can become resistant to chlorine and sanitation because of the water's pH and alkalinity.
Shock Your Pool with Chlorine to Kill Algae
This is the main event in clearing a green pool—killing the algae. Pool shock contains a high level of chlorine that will kill the algae and sanitize the pool.
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.
The only thing that kills algae is CHLORINE (or your sanitizing product, or one of the copper-based algaecides on the market). You need to raise the level of your chlorine – shock the pool – and maintain that high level until all the algae is dead. This may take 3 to 4 days. RUN THE FILTER 24 HOURS A DAY.
The use of baking soda in pools can spot treat algae
No one ever wants to see algae build up in their swimming pool. It can turn any backyard pool murky green or cause unsightly black spots on the walls and floor of any swimming pool.
So while a solar cover won't actually 'turn your pool green', it will warm your water by up to 8 degrees, so if the other conditions are right, adding a solar cover can easily accelerate algae growth, very rapidly. You need to get the water balance in your pool right before putting the cover back on.
ADD POOL CLARIFIER
The change in your pool water colour means that you have successfully eliminated the algae and can now clean it out of your pool. If your water is still green, wait another 24 hours and redo the steps from Days 1 and 2.
The most common health effects of swimming pool algae are skin infections. While the common green algae can't harm you, the bacteria feeding on the algae is harmful. When you expose yourself to algae that harbor bacteria, these infectious agents can cause rashes and breaks in the skin.
What happens if too much shock is added? You cannot overshock a swimming pool or add too much. Adding too much shock or overshocking your pool will kill off algae. The negative of adding too much shock is it will upset the chemical balance of your 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.
Green or Dark Green Pool Water:
This means there's a medium amount of algae in your water and you'll need to triple shock your pool. Triple shocking requires 3 pounds for every 10,000 gallons of pool water.
Liquid chlorine and granular shock have the same active chemical that sanitizes your pool, what changes is the strength and the way you use it. Liquid chlorine is less costly, unstabilized and comes in liquid form. Granular shock is stabilized and comes in a solid form that dissolves in your pool.
Chlorine is a sanitizer, and (unless you use Baquacil products) is necessary for maintaining a clear and healthy pool. Shock is chlorine, in a high dose, meant to shock your pool and raise the chlorine level quickly.
You Notice Signs of Eye or Skin Irritation
If you or your family members start experiencing signs of irritation during or after you swim in the pool, there may be too much chlorine present. You could notice that your eyes are itchy, red and watery, or you might notice that your skin is very dry, very itchy or very red.
Much like the veggies in your garden, when the water is cold algae won't grow. Algae is not happy if the water is below 50 degrees. The winter kit chemicals dissipate after a few weeks, but they help keep your chemicals balanced and the pool clear until your water turns into a popsicle.
Green discoloration in a swimming pool is caused by the growth of algae, a type of green aquatic plant that floats on the surface of water. Algae usually flourishes in warm water but can still take over your pool in winter if given half a chance.