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.
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.
If the pool is still very cloudy or green, you may need to shock it to make it safe to swim in again. First, make sure that the filter system is working properly and the chemicals are still at the proper levels. Next, mix up your chlorine shock (hyperchlorinate) treatment.
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.
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.
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.
Backwash only as needed. Brush the pool vigorously, several times after shocking the pool. Do not use a solar blanket until chlorine and pH level are normal. If chlorine level drops to zero within 24 hours, Repeat the shock treatment.
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.
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.
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.
Apply the shock at night time, as sunlight burns up chlorine and greatly reduces its effectiveness. Run your pump (at night) for at least 8 hours to ensure good distribution.
After Shocking Your Pool
It is safe to swim once your chlorine levels are around 5 ppm or after 24 hours. It is always best to test first!
The presence of too much algaecide can lead to a foamy pool water. Small bubbles will begin to be produced as the water is pushed through the return jet and back into the pool. Do not confuse these bubbles and foam with another common problem, which is air in your pool lines.
Algaecide should be used after each shock treatment, so it has a better chance to support your chlorine as it works its magic. Be sure to shock your pool first, then when the chlorine levels of your pool return to normal, add the correct amount of algaecide to several places around your pool while your pump is running.
Use a vacuum or backwash the pool to remove the dead algae. Apply a mustard algaecide following the label directions. Allow the water to circulate for 24 hours. Use a pool vacuum or backwash the pool again to remove the remaining dead algae.
It's pretty tough to over-shock your pool; shocking your pool two days in a row with the proper dosage for your pool volume shouldn't be a problem – and in fact, is sometimes even needed to rid your pool of algae and other contaminants.
NEVER just throw them into your pool water. This will cause them to dissolve on the floor and it can damage and create a permanent bleach stain to your liner or concrete.
If your total chlorine level is high, you will use a non-chlorine shock; if it is low, you will use a chlorinated shock. As a rule, you will need to raise free chlorine to 10 times your combined chlorine to hit what is known as “break point.” Therefore, it is good to deal with combined chlorine while it is still small.
What can happen if you go into a pool too soon after it's been shocked? There are a few potential issues. "Chlorine will react with water to produce an acid," Alan says. "The effects will be different depending on whether chlorine is inhaled or whether there is skin or eye contact."
You should wait one hour per pound of shock product added, and then test the water to confirm the pH and chlorine are in the proper range before letting anyone enter the pool.
Heavy shocking with granular chlorine will generally require 24-48 hours before the chlorine level has dropped to safe swimming levels (below 5 ppm).
The size of your pool, the efficiency of your pump and filter, and how dirty your pool is are just some of the factors you need to consider. Nevertheless, most pool cleaning professionals would advise against running a pool pump for more than 8 hours a day.
It may be cheaper to run the pump at night, but honestly you should run it 1 hour a day per 10 degrees of temperature at least, and it should be during the day. Running the pump at night should only be when you are doing a major chemical treatment such as algae clean-up.
It's best to shock your pool once the sun goes down and when the pool filter is running. If you put the shock in while it's sunny out, it will not work as well. Never shock your pool when people are swimming in it.