Generally speaking, the dosage amount of pool shock is 1 lb. per 10,000 gallons, but consult the shock package label.
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.
Although, if you overdo the shock treatment, you risk getting green hair from chlorine due to the excess chlorine oxidizing the copper in the water. You can execute a shock treatment with a few different types of pool shock, just be mindful of how much you're using.
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. 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.
The general recommendation is to use 1 pound of cal hypo shock for every 10,000 gallons of pool water, and 10 ounces of sodium hypo with around 12.5% chlorine to sanitize your pool. Make sure the pool water is at its normal level. Make sure your pool's pH is between 7.2–7.6 and its alkalinity is between 80–120 ppm.
A good rule to remember is to use one bag of shock (1 gallon of liquid chlorine) per 10,000 gallons.
Typically for granular shock, you'll need one pound for every 10,000 to 13,500 gallons of pool water.
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.
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. Only then should you introduce algaecide to get the best results.
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. Without tabs, the chlorine shock will dissipate quickly out of the water; without shock, the chlorine level will not get high enough to fully sanitize the water.
1) After shock - Sometimes pool water looks cloudy right after you apply shock granules such as cal-hypo, or liquid shock, but rest assured it's only temporary. This could be due to change in water balance – meaning your pool water temporarily goes off balance when adding these products.
Here's a pool shock treatment chart to determine the amount of pool shock necessary to raise the chlorine level above the breakpoint threshold, which is usually around 30 ppm. For example, using the table above, a 20,000 gallon pool would require 7.8 lbs of Cal-Hypo to increase the levels by 30 ppm.
Brown pool water is often caused by metals (iron) becoming oxidized in the pool water. If you shocked your pool water and it turned brown you probably have metals. Oxidized iron usually turns a brown or rusty color in the water.
But is it safe to swim in a pool with algae? Whether mild or severe, it isn't recommended. Significant amounts of swimming pool algae welcome a breeding ground of harmful bacteria that feed on algae. These bacteria pose health risks to swimmers, most commonly resulting in a skin rash.
Cloudy or milky swimming pool water is caused by seven main issues: improper levels of chlorine, imbalanced pH and alkalinity, very high calcium hardness (CH) levels, faulty or clogged filter, early stages of algae, ammonia, and debris.
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.
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.
Best Time to Shock Your Pool
The best time of day to shock pool is when the sun is down. So, experts recommend shocking your pool in the evening or at night, to make sure it does its job. Shocking during the day can be ineffective as UV rays from direct sunlight significantly reduce free chlorine levels.
To superchlorinate, add AT LEAST 2.5 ounces (5 tablespoons, 75 grams) of chlorine for every 100 gallons (400 litres) of spa water or part thereof. Adding more is fine and never a bad idea.
Often, it will look something like this. 12.5% Liquid Chlorine Pool Shock – Normal Dosage: 1 gallon of shock per 10,000 gallons of water. Shock Dosage: 2 gallons of shock per 10,000 gallons of water.
In theory, if you have a cloudy swimming pool, you can add chlorine to “shock it” and clear things up. Chlorine will get the job done. But, the amounts may vary and you may have to really pound the pool with chlorine to get the water totally clear.
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!
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. As a reminder, you want your pH to be between 7.2 and 7.8ppm and your free available chlorine to be 1-4ppm for safe swimming.