Which one should I use? The type of shock you should use will depend on the water chemistry and why you are shocking. If the water is green, I would recommend using the cal-hypo shock. If you are shocking as part of a weekly maintenance and the pool looks clean, you can use either of the 3 shocks. I normally would recommend the non-chlorine shock be used every other week (week 1 chlorine shock, week 2 non-chlorine shock, week 3 chlorine shock etc.) or before or after a heavy bather load. I would also recommend using a non-chlorine shock if bromine is used as the primary sanitizer.
Liz W Posted: 12/5/2021
Hello, We have a vinyl liner salt water pool with a Hayward salt generator. The pool water looks great however, the chlorine levels test very high. We put the cover on mid-November when the weather cooled off and turned the salt generator off. We've been having some really warm and dry weather so we pulled the cover off and also added water to the pool, in the hopes that this would reduce the chlorine levels. It has not. We are done swimming for the season but regardless it seems we should get our chlorine levels down. On a test strip Total Chlorine is easily a 10 and Free Chlorine a 5. Any suggestions would be appreciated.Reply
InyoPools Product Specialist Matt S. Posted: 12/8/2021
There are two things you can do: wait for the chlorine to dissipate naturally or drain a portion of your water and refill with fresh.Reply
Robert Mungia Posted: 7/14/2020
chlorine levels are always high how can I bring them downReply
InyoPools Product Specialist Matt S. Posted: 8/25/2020
Stop adding chlorine and the chlorine level will naturally come down. if you are dosing the pool based on a set schedule without testing, i suggest introducting a test strip test into your routine. The only reason chlorine is high is because you are adding. Start testing the water, and only add chlorine when necessary.Reply
Anonymous Posted: 7/8/2020
Can I use shock made for a salt system with a sand filter?Reply
InyoPools Product Specialist Matt S. Posted: 9/23/2020
Yes, you can. Sand filters can be used on traditional chlorine or saltwater systems.Reply
Ron Posted: 7/15/2019
If you rotate a chlorine based shock with a non-chlorine based shock (e.g., every other week as recommended), how do you test for the chlorine in the pool with a test kit, or is there another method to test the water? Thanks - great site and service.Reply
InyoPools Product Specialist Matt S. Posted: 7/16/2019
The way you test the chlorine levels wouldn't change; use test strips or a Taylor testing kit.Reply
Bob Posted: 6/29/2019
I have hard water and it’s a bit green. My ph won’t come down but everything else is good.what do I doReply
InyoPools Product Specialist Matt S. Posted: 7/3/2019
Add calcium decreaser/hardness decreaser to soften the water. Second, add muriatic acid to the water to lower the pH. Once the pH is in check, then add your chlorine to make sure you maximize its effectiveness.Reply
aaron Posted: 6/17/2019
What type of shock is best to use in a salt water pool with a pentair IC40 generator? Is there any that are harmful to the cell?Reply
InyoPools Product Specialist Matt S. Posted: 6/20/2019
You may use any type of shock options in a salt pool including liquid chlorine.Reply
Barbara Posted: 5/23/2019
Hi, I have a 18x36 above ground pool, I am in the process of clearing it of light green water. I have been using a calhypo shock. All of my chemical readings are good except my chlorine is low. I have 2bags of sodium dichlor on hand,,can I mix the two,? TxsReply
InyoPools Product Specialist Robert M. Posted: 5/23/2019
Hello Barbara - We wouldn't recommend mixing the dichlor and cal-hypo in the same bucket. However, you could add dichlor to a pool after it's been shocked with cal-hypo.Reply
Tara Posted: 4/28/2019
Thank you this is very helpful. So when would I use liquid shock? Would I use that just during the week if the chlorine level goes down?Reply
InyoPools Product Specialist Robert M. Posted: 4/30/2019
Hello Tara - The liquid shock can be used any time. Most people use tablets to maintain a chlorine level and shock the pool once a week with liquid shock Others use liquid shock daily to maintain a chlorine level.Reply
Dee Posted: 9/8/2019
Liquid Chlorine say 10% (HASA Chlorine I use) is the #1 sanitizer for pools used to keep pool water safe to swim in which requires regular maintenance of daily amounts enough to keep the ppm where they should be for your pool and given how much CYA ppm exist in the pool at the time. If you use liquid Chlorine and not "pucks" then you probably keep a consistent CYA level as recommended to help stabilize the chlorine from rapid burn off from the sun UV. Should your pool not maintain enough FC, you can begin to see yellow film forming on the walls and steps mainly in shaded areas of the pool. If you take action right away and consistently with first brushing and then "Super Chlorinating" with the same liquid chlorine but at a much higher dose and continue this for several days, it should be gone. Liquid chlorine has a component of salt because it's Sodium Hypochlorite so it will had some salt to your pool but it takes a whole lot before it's a concern. You can use Cal Hypo to shock but consider the Cal stands for Calcium which is in high concentration in shock and a mineral that you may not want to add to your plaster pool/equipment. Another shock is a Di-Chlor shock and the down side to using this one is it is has the CYA component. To much of that in your pool and your chlorine sanitizer becomes less effective, therefore it increases your chances of getting algae or you have to increase your maintenance of Chlorine, but too much CYA can lead to Chlorine lock and usually the only recourse is removing the CYA by draining or filtering the water. So that one gets expensive and why I don't use it to sanitize even for maintenance. Cleaning filters or backwashing along with brushes used is recommend and . I try not to add a lot of chemicals to my pool water because of the exposure to the human body through skin absorption when you swim so I want to keep the ppm of Chlorine and or other chemicals to a heathy limit.Reply
michelle Posted: 3/21/2019
Hi I’ve added this to my hot tub, and noticed I’m getting high chlorine readings. Previous shock I’ve used don’t do this.... can you explain why this is. ThanksReply
InyoPools Product Specialist Matt S. Posted: 3/21/2019
What are you referring to when you say "this"? If you are adding chlorine shock but was using non-chlor shock before, then that is where you difference is.Reply
Ejm Posted: 3/3/2019
I have an indoor endless pool where NO sunlight can reach. I am told not to use stabalised chlorine. Can I use a small amount of shock chlorine each day to maintain minimum chlorine levels? Do I have to shock the pool each week if i am only using shock chlorine daily. I also have a nature 2 cartridge fittedReply
InyoPools Product Specialist Robert M. Posted: 3/4/2019
Yes, you can use a small amount of liquid shock each day to maintain a minimum chlorine level. You would not need to shock the pool weekly.Reply
Theron Posted: 4/14/2020
How often should I shock a 1013 gallon indoor pool that gets no sunlight? Would a non-chlorine shock be best since I lose chlorine very slowly?Reply
InyoPools Product Specialist Robert M. Posted: 4/14/2020
It really depends on your free chlorine level. If the free chlorine is staying between 1-3 ppm, you won't have to "shock" it with chlorine. You could use a non-chlorine shock after someone uses the pool.Reply
Matthew Posted: 8/20/2018
Hello Joan - when using Cal-Hypo shock, it should be pre-mixed before adding it to the pool. Cal-Hypo is a strong enough shock to where it can bleach out your liner if left undiluted.Reply
Joan Posted: 8/4/2018
We currently have a in-ground vinyl lined pool,we originally were shocking with a Cal Hypo type of shock from pool store and the bucket stated no pre-mixing needed, just broadcast directly to pool. Is that the best type of shock to use for a vinyl liner ? Do you think the ones that state no premixing needed are OK to use? Thank you so much.Reply
Inyopools.com Posted: 7/27/2018
Hello Jacqueline - You will definitely need to shock the pool if you intend to keep the current water in the pool. We'd recommend a cal-hypo or liquid chlorine shock. We also recommend reading our blog titled "How to Clean a Green Pool".Reply
Jacqueline Posted: 7/26/2018
We have a 10,000 (approx) gallon in-ground pool. It came with the house which was vacant for 6 years. The pool was winterized and covered. The water is green/black. We were told that we might want to shock it before we start the cleaning process. Would you recommend this?Reply
Inyopools Posted: 7/18/2018
Hello Scale Last Year - Calcium hypochlorite can lead to calcium scale. If scale has been an issue, we recommend using sodium hypochlorite (liquid chlorine).Reply
Scale last year Posted: 5/21/2018
Last year we had a calcium scale problem in the shallow end of our pool. We had used calcium hypochlorite to shock the pool. Would that have caused the scaling and, if so, what shocking product do you recommend?Reply
Inyopools Posted: 1/7/2018
Anonymous (shock) - Here is the link to the Calcium Hypochloride Shock that we sell. We feel it is one of the best brands in the market.Reply
Anonymous Posted: 1/2/2018
Which is the best brand granular calcium hypochlorite to use?Reply
Hidden Valley Posted: 7/16/2017
Would you use a non chlorine shock on a commercial pool.We use a non chlorine shock with 3 inch Tablets Di chlor.Its hard to get a chlorine reading.It takes severial minute for the results ,Why.Its 40.000 vinyl DE filters.Reply
InyoPools Product Specialist Dennis R. Posted: 6/9/2017
Denese - Yes, you can you any of the shock options in a salt pool including liquid chlorine.Reply
Denese Posted: 6/8/2017
Can I use liquid pool shock in salt water system at spring start upReply
InyoPools Product Specialist Dennis R. Posted: 7/25/2016
dawn - See our guide on "Above Ground Pool Maintenance - step 8". Steps to emphasize - this may take several days to eliminate all the algae:Get your water flowing and leave the pump running continuously until water is clear.
Get any large debris out of the pool with a net.
Add shock to get the chlorine level up to 10 ppm.
Check the chlorine level twice a day. Add more shock if it goes below 5 ppm.
Clear the filter twice a day to remove embedded algae.
Brush the entire pool once a day.
Continue to monitor the Chlorine level until the pool is clear. Then maintain Chlorine at 3-5 ppm
Check chemical balance especially pH and CYA levels.
Reply
dawn Posted: 7/23/2016
I have a round metal frame pool 12 by 36.I filled it up 3 days ago it's already green.I bought some pool essentials shock and a 3-way test kit.I don't know anything about this stuff I haven't even turned pump on since I got it .HELP PLEASE!!Reply
Anonymous Posted: 5/10/2016
Thank you for explaining the different types of shock. Very helpful.Reply
InyoPools Product Specialist Dennis R. Posted: 7/24/2014
merbear - The most important consideration to avoid heater corrosion is to keep the high concentration of chlorine from getting into your heater. If you have a chlorinator or salt chlorine generator, make sure they are placed into your piping after the heater as the last unit in the return piping. And place a check valve between the chlorinator / SCG to prevent high chlorine water from backing up into the heater when the pump is shut off. The type of shock you use does not affect heater corrosion as far as I know. Lastly make sure you maintain water balance to reduce corrosion over time.Reply
merbear Posted: 7/23/2014
We gave an above ground pool with a gas heater. We have been told conflicting info on which aspect of chemistry us most important to avoid heater corrosion. With respect to shocks and calcium levels can anyone advise what type of shock is best? Help!Reply
Belle Posted: 6/5/2014
Thanks for the helpful info.I now know I have not been shocking my pool because Ive always used non-chlorine shock. On the up side I never had any problems.Reply