Bromine too high

[jandersen13]

I’ve been struggling with a high bromine level and low pH and TA.

I have a floater with 1 inch bromine tabs in it. It’s fairly small and fits about 8 tabs. I have the holes open about 50% and the tabs are all gone in about 4 or 5 days. My tub is 410 gallons. I have been just filling it back up each time it’s gone.

Today I added Pro Team Metal Magic Spa (high iron in fill water) as my weekly dose. I had been using Natural Chemistry MetalFree but switched today to Pro Team Metal Magic Spa based on recommendations here. The water turned yellow almost immediately like the iron came out of solution. I was puzzled and added in Natural Chemistry MetalFree again. Let us run for a few hours but still fairly yellow.

I checked TA and pH and both were VERY low as in not registering. I added 5 ounces of soda ash mixed up and in to the water. Almost immediately the yellowish water went to mostly normal.

So a few questions. Did Pro Team Metal Magic mess up TA and pH? I can’t figure out why my TA and pH would have dipped so low without having added anything. Should I not used Pro Team Metal Magic Spa any longer and stick with Natural Chemistry MetalFree?

Also, any suggestions for a better floater? I feel like mine might be putting too much in. Any better way to regulate it?

 

[jandersen13]

Does anyone have any thoughts? Or is it just trial and error with the bromine floater until I figure out how much it should be putting in?

 

[Mdragger88]

You haven’t listed your bromine level but you should be maintaining 4-6 ppm as listed in the sticky

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

Originally Posted by waterbear There is a lot of misinformation on the proper way to use Bromine so I hope this primer is helpful. First, you need to establish a bromide reserve in the water. Bromine tablets can do it by themselves but it can take literally weeks until enough dissolves. Some...

www.troublefreepool.com

I believe it is trial & error w/ the floater - try keeping it almost closed. Also I noticed some brands of tablets recommend using only 3 or 4 tabs every 5-7 days for a 300 gal spa so maybe put a fewer as well.
PoolMath effects of adding doesn’t have a place for calculating bromine’s effects but I suspect it’s rapid increase is the cause of your ph/ta crash. Not sure about the sequesterant’s effects. Someone with more bromine/ chemistry knowledge should hopefully be along in a bit to explain in more detail. The whole bromine/bromide thing is kinda greek to me & seems complicated to maintain so I stick to chlorine.
@JoyfulNoise

 

[JoyfulNoise]

Bromine tablets are typically quite acidic. They will drop your pH and TA fairly quickly. Metal Magic can also reduce pH as well. The yellow coloration was likely the result of low pH causing a small concentration of elemental bromine to form from the hypobromous acid. When you added the soda ash, your pH was restored and the sanitizing bromine converted back to mostly HBrO.

If your going to run your hot tub with bromine from brominating tablets, then you need to keep a close eye on your pH and TA. Using baking soda to keep the TA up should be sufficient.

Does your tub have an ozonator?

 

[jandersen13]

Mdragger88 - thanks! I will take a further look into the instructions for the bromine tabs I have. I thought it said to just keep a floater full and as they are gone, add more (I might have just made that assumption too, so will double check). I recently switched to bromine as I'm not able to add chlorine in every day, so thought this could work for me.

JoyfulNoise - Ok that makes sense and helps to explain it, thank you! I was checking every week for pH and TA, but will do that more often now. My tub does not have an ozonator but it does have a UV light (Sundance ClearRay system). Does this make any difference?

 

[JoyfulNoise]

Mdragger88 - thanks! I will take a further look into the instructions for the bromine tabs I have. I thought it said to just keep a floater full and as they are gone, add more (I might have just made that assumption too, so will double check). I recently switched to bromine as I'm not able to add chlorine in every day, so thought this could work for me.

JoyfulNoise - Ok that makes sense and helps to explain it, thank you! I was checking every week for pH and TA, but will do that more often now. My tub does not have an ozonator but it does have a UV light (Sundance ClearRay system). Does this make any difference?

No, the UV is just for supplemental oxidation of bather waste. My concern about ozone was that if it were present it would oxidize spent bromide back into bromine abs could cause high bromine levels with the use of a floater. But since it’s not there, then no concerns.

Bromine tablets can be tricky to get right. Temperature has a big effect on their dissolution rate so you may need to play with the standby temperature a bit (turn it down) to get the right feed rate.

 

[jandersen13]

Just checked bromine level tonight with K-1000 and it was off the charts, orangey color. TA is 80 and pH is 7.5. I took the bromine floater out to wait for the level to go down.

Is the best path forward to just add the floater in every once in awhile? I thought I’d just have it in all the time...but that doesn’t seem to be the case. Anyone have experience with a bromine tab floater?

 

[irekz]

Friend of mine uses bromine and they use floater only when going on holidays.
For day-to-day use they just just bleach to activate bromine as needed (large dose after the soak, small one every day based on free bromine test). This might be easier and more reliable.
Note: this method requires that you have established bromine bank first.