This algae is difficult to get rid of and won't be killed by any normal dose of a sanitiser such as chlorine or an algaecide. You need to kill it by super shocking your swimming pool (a high dose of chlorine and acid) or else you'll be battling with it all season long!
When there is not enough chlorine in your pool water, green algae—which can float freely or attach to the walls and floor of your pool—can grow. Thus, in many cases, the most efficient way to get rid of algae is by shocking your pool water with chlorine.
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.
Can you put too much shock in a pool? SKIMMER NOTES: It's unlikely but it could happen. It would take a lot of shock to really make the water unsafe for swimming. The best way to make sure you're safe to swim is to test your pool water and make sure free chlorine levels are between 1-4ppm for healthy swimming.
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.
A pool filter should be run for a minimum of 6 hours after shocking a swimming pool. This is to allow the filter to clean the water and give the shock enough time to fully mix with the pool water. Running the filter after shocking for 24 hours to 7 days is necessary if the pool has a large amount of algae.
Give the shock a good 12 to 24 hours to work it's magic. If the algae hasn't cleared up after 24-48 hours, clean and brush the pool and add another shock treatment.
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.
While shocking and adding algaecide is effective in getting rid of algae, it should not be done together. This is because when you mix chlorine and algaecide together, it renders both of them useless. Hence, you should first shock the pool and wait for the chlorine levels to fall below 5 PPM.
When the chlorine has completely finished working, the algae in the pool will turn a white/gray color and will either settle to the bottom of the pool or be suspended in the water. There shouldn't be any more green color and the water visibility should be improving. Run the filter 24/7 and backwash as needed.
Light Green or Teal Pool Water:
To double shock, you will need to add 2 pounds for every 10,000 gallons of water. For instance, if you pool is 20,000 gallons, you will add 4 pounds of shock.
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.
Green algae, unlike its black counterpart, is a true algae; it isn't resistant to chlorine, so you can control it by shocking the pool. If you don't want to spend a lot of money on expensive pool chemicals, you can shock with household bleach.
To kill green algae, add a chlorine-based shock to the pool. Give the pool a thorough brushing and run your filter to remove the dead algae from the water. After you've killed the algae, you'll need to add a clarifying product (flocculant) that will cause the skeletal remains to sink to the bottom.
Shock is chlorine, in a high dose, meant to shock your pool and raise the chlorine level quickly. Chlorine tabs (placed in a chlorinator, floater, or skimmer basket) maintain a chlorine residual in the water. You do need to use both tabs and shock.
We typically recommend using a calcium hypochlorite (cal hypo) shock when super chlorinating a pool. Just keep in mind that this type of pool shock has a small amount of calcium and will cloud the water for up to 12-24 hours in certain situations.
How Often Should I Shock My Pool? Shocking your pool regularly will help to keep the water clean and free of contaminants. You should aim to shock your pool about once a week, with the additional shock after heavy use. Some tell-tale signs that your pool needs to be shocked are cloudy, foamy, green, or odourous 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.
"Shocking” refers to the process of adding chlorine or non-chlorine pool chemicals to the water in order to raise the "free chlorine” level. The goal is to raise this level to a point where contaminants such as algae, chloramines and bacteria are destroyed.
Typically for granular shock, you'll need one pound for every 10,000 to 13,500 gallons of pool water.