See-sawing FCl in bromine tub


Mar 1, 2012
Southern California
I posted a while back that I bought a house that came with a hot tub, and knew nothing about it. Eventually I ended up hiring a local hot tub company to come out and do an Ahh-Some purge, clean it, refill it, and get it started right. It seemed ok at first, but now I'm having a problem where I literally CAN NOT dial in the bromine level properly. I'm Using Poolmaster 22211 Smart Test strips, and Leisure Time chemicals (primarily because it's what the prior owners had been using, and they are easily available).

The guy who set up the hot tub told me to add half a cap full of the "Renew" shock once a week or after every time we use the tub, and he said to keep bromine tablets in the floater. The first time I did that, I checked a day or two later, and the FCl reading was off the charts high. I assumed I had set the floater setting too high, so I pulled it out and emptied it, and gave the tub some time for the excess bromine to dissipate. Eventually the readings started coming down, and it got to the point where it was actually reading low on the scale. So I tried again, I loaded up the floater with tablets, and adjusted it so only about half of a tablet was exposed, which seemed really minimal (I was sure it would be too little), but now here I am with it reading off the charts high again.

What am I doing wrong? Do I really need to dial the floater in even less? Is adding Renew every week as he told me to do messing it up? Should I not be filling the floater all the way with tablets? Is there possibly something else wrong? I don't think I'm a stupid person, but this is making me feel dumb. I don't think it should be rocket science....


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Here is our procedure for using bromine...

You will find folks here prefer using chlorine or a Salton Mini SWG in their hot tub.