How to shock a salt water pool

[bosco0633]

Ok quick question. I have an 18,000 gal inground pool. I have a t-15 Hayward cell and I keep my chlorine generator at 10%. That keeps me at 3.5pm with chlorine. My friend suggested that I turn the generator to 15% for a few hours after a heavy swim load to shock it. If I let the generator percentage stay at 15% it will bring my chlorine up to 5ppm.

I was also told not to super chlorinate as it will lower the life expectancy of my generator. Does this seem right by increasing the percentage to shock??

 

[dmanb2b]

You can raise the percentage sure and you got sound advice about not superchlorinating with the cell. For a quick boost, you can also just add some bleach and leave the SWG alone. A saltwater pool is a chlorine pool and hence, when needed to shock, you should do it with liquid chlorine. But what you describe is just a boost of FC perhaps before a pool party? Not really what we call shocking.

 

[bosco0633]

Ok so why shock a pool then? And how do you do the bleach way that sounds alot cheaper

 

[Poolschoolgrad]

With Stabilizer level (CYA) of 60, I try to maintain the chlorine at 4.
At CYA= 70, then Chlorine at 5 is fine.
With normal family usage, as long as the chlorine stays above 3 ppm then there would not be a reason to adjust the output %.

Increasing output % in advance of a heavy bather load and after a heavy bather load is not "shocking" just smart chlorine management.
Before a pool party, increase the output to 15% for a few hours and leave it there for a few hours after the party.
A few active people in a pool can use up 1 to 2 ppm of chlorine.
If there are a lot of active people in the pool and the chlorine level drops to 1 or 2 after the party, then leave the Aquarite at the higher setting over night to recover from the lower chlorine level and reset it to 10% the following morning.

PSG

 

[zea3]

Ok so why shock a pool then? And how do you do the bleach way that sounds alot cheaper

To answer your question, we only advocate "shocking" the pool when there is an algae outbreak, fecal contamination, or in specific cases where someone has deposited something in the pool that shouldn't be there, such as motor oil, topsoil, cooking oil, ect.

We advocate using bleach or liquid chlorine when there is a need to complete the shock process on the pool. Using The Pool Calculator plug iin a set of current test results and use enough bleach to raise the FC to shock level for your pool. Keep the FC at shock level as much as possible until you pass
the overnight test.

When you need to boost the FC for a party, you can use the SWG as has been posted above, or you can use bleach and the pool calculator to figure out how high to boost the FC.

 

[DigitallyChallenged]

My SWG is quite a bit oversized for my pool. I run it at about 5% for 14 hours a day to keep my levels o.k. In a few hours at 100% my levels climb significantly. If I can get to a chlorine level of 30 overnight, or sooner, would it be alright to use the generator vs adding bleach?

 

[frustratedpoolmom]

Sure we recommend liquid because most cells can't produce it fast enough, and it shortens the life of the cell. In your situation it doesn't really seem it would be an issue.

 

[boomingsooner]

Hey guys,
I have a 14,000 SWG pool in Arizona and my cell runs at 80% 365 days a year. I still have some problems with black algae spotting in places, I use 1 gallon of bleach a week at least in the summer. I can't imagine running the cell at these levels. How bad am I messing this up??
Thank you.
Brett

 

[Akronstax]

bosco0633, boomingsooner, - what are you CYA levels you are at? You can't make a judgement about an FC amount without a CYA level. They go hand in hand.

 

[pooldv]

FC needs to be maintained based on your CYA level based on this Chlorine CYA Chart.

Sounds like your cell may be undersized for your pool. We recommend 2-3x larger for a SWG, so probably a 40k generator.

You definitely need to SLAM Your Pool

Welcome to TFP!

Here are some intro Pool School articles to read while you SLAM.
TFPC for Beginners
ABC's of Pool Water Chemistry

Here is the Water Balance for SWCG pool.
Here are the Recommended Pool Chemicals
Use PoolMath to figure out how much to add.