Bromine disappears very quickly...??? (I'm still new to this)

[gcaver]

I am a chemist who just bought a spa a month ago, so I have had an absolute ball leaning the ropes of spa water care. I have done a ton of reading on the forum here and other resources - love it!

Quick question: I spiked my Br up to around 10-15ppm yesterday with sodium bromide (yes, purposefully) because I wanted to do a little experimenting with how long it takes for levels to fall in my tub. I planned on doing a full water change soon anyways. I confirmed with strips that I had hit my target then walked away for the night. This morning, to my absolute amazement, my Br levels were gone (1ppm at best). So I repeated the spiking again to 10-15ppm. Checked it 2-2.5 hours later and it's gone again!

What the heck is going on here in my water?? FYI, I also have 3 Br tabs in my filter basket (I know it's not ideal, floater has been ordered). My spa is covered all the time, is never in sunlight (under a porch overhang), and is only used at night; so it's not breakdown from the sun.

The ONLY thing I can think of is that I need to shock with Cl in addition to the Br loading so that the Cl can oxidize and "activate" the Br...??? Is that my problem?

Any and all help would be greatly appreciated!!

 

[mknauss]

Welcome to the forum! :handshake:

How do I use Bromine in my spa (or pool)?

I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.

 

[gcaver]

OK, I've done my reading. But I still cannot find a matching description of my problem; or perhaps I am just straight up misunderstanding some things.

Even when I add chlorine shock, the spike in bromine level reading on my strips seems to only last a few hours, then it's right back to reading 0-1ppm bromine.

What am I not getting here?

 

[jseyfert3]

Do you have a better test kit? Test strips are not very reliable. You want an FAS-DPD test kit, such as the Taylor K2106. You could also use a TF100 or Taylor K2006, but those are for chlorine and you'd have to multiply the result by 2.2 to get ppm bromine.

I'm not very familiar with bromine as I run chlorine (seemed easier, still think it is based on posts I see from bromine users), but if the strips can be trusted at all it sounds like you have a huge sanitizer demand. Prior to this spiking test, did you maintain an adequate level of bromine and what was the bromine demand (in ppm/day)?

 

[gcaver]

I have a Taylor K2106 on order. Should be here Friday.

Prior to this experiment/problem, I used chlorine. This is my first attempt at going bromine, so I don't really think I was ever able to establish a stable bank (even tho I used the right chem products). If anything, I tend to agree that it does seem like I have a huge chlorine demand.

 

[jza1736]

Did you change the water when you switched to bromine?

Did you add sodium bromide to establish a bank? How much?