What should my free chorine be after shocking spa ?

[kurt6137]

I have a 2013 Hot Springs Sovereign, I had a problem with cloudy water, due to the fact, I did not shock it in 2 weeks, I shocked, but it was still milky cloudy, I used a clarifier, which helped, cleaned filters each time, shocked again, much better today, cleaned filters again and added clarifier again today, I measured my free chlorine and it was like at zero, why ?  I have a ozonator, the total chlorine looks ok, but free chlorine is close to zero.

[Flyonthewall]

plucked this off the web.  basically when your total chlorine and free chlorine get seperated you need to shock it.  chlorine will suffice for this, but i think non chlorine shock (like renew) works better in a hot tub.
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Chlorine - The Analogy:
We can compare Chlorine to Gasoline in our car.  If we have Chlorine in our pool it is like having gasoline in our car.  The chlorine is available to kill bacteria and the car is ready to be driven.  As Chlorine kills bacteria and is used, the available level decreases just as the gas in our car decreases as we drive around.  In our car, when we burn gas, the used gas is turned into exhaust and goes out the tail pipe.  When Chlorine is used it turns into a "Chloramine" or used chlorine but stays in the water.  We must "Shock Treat" the pool or spa water to allow the Chloramine to turn into a gas and escape the water.  If we were to put a potato in the tail pipe of our car, it would cause the car to run poorly and we may even smell the exhaust inside the car.  This is similar to what happens if we do not properly shock treat the pool/spa water.  Chloramines will build up in the water and not allow the "Free Chlorine" to work effectively and we will begin to smell a chlorine odor.  Shock Treating the pool/spa is like removing the potato out of the tail pipe on our car!



Chlorine - The Basics:
 Maintain the proper residual of Free Available Chlorine
 Shock Treat on a regular basis to prevent Chloramine (used chlorine) buildup and odor  If there is a difference in the Free Chlorine and Total Chlorine test results, shock treatment is needed.
 Pools - Shock treat every two weeks, every week when it is 85º or above, or after a rain or heavy bather load.
 Spas - Use Oxy-Brite and shock treat on a weekly basis for residential spas and daily for commercial spas.