Disappearing Shock

Lyd

Well-known member
Jul 24, 2015
60
South County, Rhode Island
Good Morning, All and I hope everyone is doing very well. I have an interesting issue that I have never experienced before in my hot tub.
Usually, after each tubbing, I add 1 ounce to 1.5 ounces of 12% liquid shock and all is fine at the next days readings. This is a bromine tub, no floatie.

Lately, I have had to put in between 3.5 and 5 ounces of shock just to keep the readings between 1.25 and 2.5. It has been a long time since my tub has acted up so I forget the usual protocols. I am thinking I either need to change the water or shock it over 10ppm and leave it alone til the numbers drop. Leaving it be and letting the level drop of it's own accord is not something I am good at doing. I do not think it needs the water changed as I last changed it on Halloween, so that is...3.5 months ago. Your kind advice please?
 

RDspaguy

In The Industry
Mar 21, 2020
1,090
Cabool, Mo
I am no chemistry expert, but I would suspect that your bromide bank is low and you are not reading bromine but chlorine. Or you have developed biofilm that is eating up your bromine. I would add some sodium bromide and see. If it doesn't do the trick, purge with Ahhsome.
If your tub has ozone you may be seeing the results of ozonator failure as well. Without the added oxidation from ozone you may need more shock to see the same results.
Incidentally, I drain and refill every 3 months.
 

Lyd

Well-known member
Jul 24, 2015
60
South County, Rhode Island
Thank you, RDspaguy. I just checked it and it is about 1.25. I will shock it and leave it alone to drop naturally. I have never added more bromide than at each new fill in 6 years so that spooks me a bit. I will add more bromide in a week if this does not work. I usually go 6 months or better between drain, Ahhsomeness and refills. My water is always crystal clear too, thanks to this forum!!! If I screw it up with the bromide, then I will drain. Thank you again, I appreciate your time!!