Baqua to Chlorine conversion with cya of 40.

[Uckybay]

Well.... that sucks.

When the bromide is oxidized into bromine and the sun hits it, does it turn back into bromide so the process never ends? The bromide will never be entirely "used up"?

 

[JoyfulNoise]

Well.... that sucks.

When the bromide is oxidized into bromine and the sun hits it, does it turn back into bromide so the process never ends? The bromide will never be entirely "used up"?

Sort of.

There are two pathways for spent bromide to be oxidized - the formation of sanitizing bromine (Br+ in the form of hypobromous acid) and the formation of bromate anion (BrO3^-). The vast majority of the bromide gets converted to hypobromous acid while a small fraction is oxidized to bromate. So, in reality, it would take a really really really long time to get rid of the bromide if you rely on bromate formation.

And bromates are carcinogens anyway so there’s that …

 

[Uckybay]

I found an interesting article regarding this exact scenario. Trouble Free Pool and @chem geek are mentioned in it.

Bromine or Chlorine? What's in Your Pool? • Pool Chemistry Training Institute

This happens more than I realized. Many chemical manufacturers use sodium bromide in their algae control products or specialty products like yellow something

poolchemistrytraininginstitute.com

It looks like I can do some testing to see if I still have a bromine pool, which I am fairly certain that I do since I can't keep any chlorine in the day, but this simple test can prove it. What still seems to be uncertain is the amount of time required for the bromide/bromine to be reduced to a low enough ppm to stop causing the chlorine to react with it.

 

[Mdragger88]

I found an interesting article regarding this exact scenario. Trouble Free Pool and @chem geek are mentioned in it.

Bromine or Chlorine? What's in Your Pool? • Pool Chemistry Training Institute

This happens more than I realized. Many chemical manufacturers use sodium bromide in their algae control products or specialty products like yellow something

poolchemistrytraininginstitute.com

It looks like I can do some testing to see if I still have a bromine pool, which I am fairly certain that I do since I can't keep any chlorine in the day, but this simple test can prove it. What still seems to be uncertain is the amount of time required for the bromide/bromine to be reduced to a low enough ppm to stop causing the chlorine to react with it.

This is very interesting- I have tried to find the original posts but haven’t had luck.

 

[JamesW]

You can't tell bromide from chloride.

Bromine creates as many or more combined products as chlorine.

Your best bet is to get a SWG.

 

[JamesW]

If you have a variable speed pump and an SWG, you can maintain an adequate chlorine level by running 24/7 because it is is continuously generating.

Even if you have a lot of bromide, it will work as long as you generate at the correct rate, which can be confirmed by doing an OCLT.

If you have a lot of bromide, the level will stay at maybe 3 ppm and when the bromide is gone, the level will rise significantly higher.

Target adding about 4 to 5 ppm chlorine per day and see where the FC levels off.

 

[Uckybay]

Your best bet is to get a SWG.

The rust factor with saltwater and a steel wall above ground pool is risky and I feel it will shorten the life of my pool unnecessarily. Even the above ground pools that are sold as "saltwater safe" are prone to rust.

I have an intex brand SWG that is not in use, but I'm not sure if it is large enough to keep up with demand. I used it several years ago in a tube frame intex pool that only lasted 2 summers due to the amount of rust in the frames from the saltwater.

 

[Uckybay]

This is the clearest the water has ever been in this pool. Gus the temperature duck in the corner says the water is still only 70 degrees.

 

[JoyfulNoise]

The rust factor with saltwater and a steel wall above ground pool is risky and I feel it will shorten the life of my pool unnecessarily. Even the above ground pools that are sold as "saltwater safe" are prone to rust.

I have an intex brand SWG that is not in use, but I'm not sure if it is large enough to keep up with demand. I used it several years ago in a tube frame intex pool that only lasted 2 summers due to the amount of rust in the frames from the saltwater.

Guess what - your chlorine pool is already a saltwater pool . If you are regularly adding liquid chlorine and acid, your pool water will build up chloride. Many people when they switch to SWGs test their water and realize they only need to add a few bags of salt because their salinity is nearly 2/3rds of the way there.

If your pool is prone to rust, the SWG and salinity are not going to accelerate that, it’s going to happen no matter what. The salinity of a salt water pool really isn’t “saltwater” , it’s the low end of “brackish” at best.

But, of courses, it’s your pool and your money so you get to decide. The SWG helps to burn off the bromide a little faster than normal because it too will generate some bromates. So it can help to keep your sanitizer level supported while you wait for a better time to drain and refill the pool. It’s just a bandaid measure to keep your pool from going green because if you run too low on sanitizer, algae can build up fast. You’ve seen that with Baquacil - once algae or mold gets going, it’s hard to stop a it. It’s less of an issue with chlorine but it can still happen if you let the sanitizer get too low.

Algae wins by sheer strength of numbers - billions of algae microorganisms able to double their colony sizes in less than 4 hours … it’s like the zombie apocalypse hoard overrunning your fort. If you don’t have the BFG to wipe out the hoard, you’re done for …

 

[JamesW]

Also, the water contacts the liner, not the steel walls.

 

[Mdragger88]

This is the clearest the water has ever been in this pool. Gus the temperature duck in the corner says the water is still only 70 degrees.


View attachment 500192

It is certainly looking great stay on top of chlorine/sanitizer and it will stay that way. If the fc/sanitizer demand doesn’t get better soon you’ll be better off replacing water as I am sure water is cheaper than bleach & some more cya. Then you’ll know what you’re working with.
The factors that James mentioned about the combined stuff is likely why the testing method mentioned in the article isn’t in the bromide/bromine wiki.

 

[duraleigh]

I have a gut feeling that "BFG" bypasses the "dirty word filler but I really like it!

 

[Uckybay]

It is certainly looking great stay on top of chlorine/sanitizer and it will stay that way. If the fc/sanitizer demand doesn’t get better soon you’ll be better off replacing water as I am sure water is cheaper than bleach & some more cya.

We had nearly 3ft of rain since last fall after the swimming season was over. All of that went into, and out of the pool. Hopefully that volume of water helped with flushing some of the bromide out.

 

[JoyfulNoise]

We had nearly 3ft of rain since last fall after the swimming season was over. All of that went into, and out of the pool. Hopefully that volume of water helped with flushing some of the bromide out.

The problem is rain water has very low TDS and pool water has very high TDS. The less dense rain water will float on the more dense pool water and they will not naturally mix much. So any overflow of water will be mostly rain water.

To use rain water effectively, you have to drain down the pool and let it fill back up. Then mix it with some form of agitation.