low bromine levels

[gcasey4]

At the enod of season last year I was having a hard time keeping bromine in my 24,000 gallon above ground pool. Before opening this yeat I replaced my old cracked filter witha new 22" hayward sand filter. I drained t2/3 of the pool water and refilled the pool.
I shocked with six pounds of nonchlorine shock.
After running the filter for 24 hour there was no bromine. I checked to be sure the bromine dispenser was working properly which it seems to be.
Adding a pound of bromine in the skimmer basket failed to bring the bromine level up.
PH and alkalinity are good and the water is crystal clear. I am totally confused. I hope someone can enlighten me. :?

 

[chem geek]

Welcome to TFP!

What kind of test kit are you using? If it's a DPD kit where you compare shades of pink/red to a standard, then your bromine level may be so high as to bleach out the test. This is one reason why we recommend the FAS-DPD test kit or also have an OTO test kit as a backup since it will not bleach out.

Also note that when using non-chlorine shock to generate bromine, you need bromide in the water and you just got rid of 2/3rds of it. Nevertheless, I suspect you have too much oxidizer in the pool and it is bleaching out the test. 6 pounds of non-chlorine shock (43% MPS) in 24,000 gallons would be only 6 ppm FC equivalent so 13.5 ppm Total Bromine. That's on the edge of bleaching out the test depending on the specific brand of test you are using -- some of them bleach out completely at 10 ppm FC while others only partially bleach out at that level. Bromine may bleach out the test more readily than chlorine, though I'm not sure of that. If the issue is one of bleaching, you can dilute your pool water sample with tap water (say, 50/50) to see if you then get a bromine reading.

What kind of fill water did you use? If you used well water, then it could have organics in it and the bromine got used up oxidizing those.

 

[gcasey4]

I thought of the bleaching problem. I used an OTO and got the same results. No bromine. The OTO is at least a year old, so I will try a new one.

 

[gcasey4]

Here is the latest in my quest to keep bromine in my pool. I bought a new five test kit. Not test strips. After adding four pounds of non chlorine shock eight hours later I had 3ppm of bromine. 24hours later I had zero. Any suggestions.