Why Does Bromine Keep Going To Zero?

[Jazser]

I have a new hot tub - posted earlier that I put in PH stable (buffer) and that I had issues with soft white flakes suspended in the water (which I assume was calcium). The good news is that I have been able to filter out most of the white stuff and I've got hardness, PH, and alkalinity all within the ideal ranges on the test strips. However, every morning when I go out to test - Bromine is at zero. So the last 2 mornings I tried some shock, and it raised a little, but not much. So I then added granulated brominating concentrate - and the level shot up to the high end of the strip (20ppm) even after circulating in the tub with jets for 15-30 minutes. Next morning - bang, back down to zero again.

Was there just so much nasty stuff in the water that its using up all the Bromine every day? We've (2 adults an a child) only been in the tub twice - and not for very long.

[Hillbilly Hot Tub]

I have a new hot tub - posted earlier that I put in PH stable (buffer) and that I had issues with soft white flakes suspended in the water (which I assume was calcium). The good news is that I have been able to filter out most of the white stuff and I've got hardness, PH, and alkalinity all within the ideal ranges on the test strips. However, every morning when I go out to test - Bromine is at zero. So the last 2 mornings I tried some shock, and it raised a little, but not much. So I then added granulated brominating concentrate - and the level shot up to the high end of the strip (20ppm) even after circulating in the tub with jets for 15-30 minutes. Next morning - bang, back down to zero again.

Was there just so much nasty stuff in the water that its using up all the Bromine every day? We've (2 adults an a child) only been in the tub twice - and not for very long.

When you started up the tub did you use sodium bromide to form a reserve of bromine? The bromine shooting up to 20 may have been a misreading because brominating concentrate is a dichlor/bromine mix and the dichlor may have read high. If you had no reserve to start, it will take upwards of a week plus to form one with tablets. this would exsplain why when you shock it is only registering a small amount of bromine...because there is only a small amount to re-establish.

[Jazser]

I have a new hot tub - posted earlier that I put in PH stable (buffer) and that I had issues with soft white flakes suspended in the water (which I assume was calcium). The good news is that I have been able to filter out most of the white stuff and I've got hardness, PH, and alkalinity all within the ideal ranges on the test strips. However, every morning when I go out to test - Bromine is at zero. So the last 2 mornings I tried some shock, and it raised a little, but not much. So I then added granulated brominating concentrate - and the level shot up to the high end of the strip (20ppm) even after circulating in the tub with jets for 15-30 minutes. Next morning - bang, back down to zero again.

Was there just so much nasty stuff in the water that its using up all the Bromine every day? We've (2 adults an a child) only been in the tub twice - and not for very long.

When you started up the tub did you use sodium bromide to form a reserve of bromine? The bromine shooting up to 20 may have been a misreading because brominating concentrate is a dichlor/bromine mix and the dichlor may have read high. If you had no reserve to start, it will take upwards of a week plus to form one with tablets. this would exsplain why when you shock it is only registering a small amount of bromine...because there is only a small amount to re-establish.

Ahhh! Ok I will get some Sodium Bromide. I've been using Brominating Concentrate - thought they were the same. Thank you!

[Hillbilly Hot Tub]

what is your general regimine? Are you using tablets or just brominating concentrate?

[Kapp]

We have same situation. Using bromine tablets in floater. The only time I can get Bromine to register at all in when I shock it once a week. Then its off the charts for about 1 day then zero again and again. I know its in there and tabs. One person suggested our cloudy (Milky water when jets turned on) was due to too much bromine. I cut back to two tabs in the dipenser and opened to required level for our number of gallons. Now nothing, won't even show on test strips (unless I shock) yes we have an ozonator...in other words..I have no idea how much is really in there...too much or too little because I can't what I feel is a "true"reading. the other issue is still not solved (Milky water when jets turned on otherwise crystal clear, all chem levels except bromine show perfect) clears up in less then a minute to crystal clear. Its like pouring gallons of milk (from millions of tiny bubbles i guess) right into to tub when you turn on the jets and wondering if this in not Bromine level related. thanks

[Hillbilly Hot Tub]

We have same situation. Using bromine tablets in floater. The only time I can get Bromine to register at all in when I shock it once a week. Then its off the charts for about 1 day then zero again and again. I know its in there and tabs. One person suggested our cloudy (Milky water when jets turned on) was due to too much bromine. I cut back to two tabs in the dipenser and opened to required level for our number of gallons. Now nothing, won't even show on test strips (unless I shock) yes we have an ozonator...in other words..I have no idea how much is really in there...too much or too little because I can't what I feel is a "true"reading. the other issue is still not solved (Milky water when jets turned on otherwise crystal clear, all chem levels except bromine show perfect) clears up in less then a minute to crystal clear. Its like pouring gallons of milk (from millions of tiny bubbles i guess) right into to tub when you turn on the jets and wondering if this in not Bromine level related. thanks

When you say your reading is sky high after a shock, how long are you waiting to test the water after shocking? You have to wait a while for the chems to do their work. If it is at zero the next day, you did not shock enough. Zero means there is something in the water chewing up the bromine. What is the spa usuage? You may need to super shock since the reading is dropping, indicating that you have not oxidized everything, and you may need to add shock once or twice during the week if you are using the tub daily. Did you start with sodium bromide to form a reserve? How long since your last water change? Are there metals in the water? Swimsuits? Are you putting swimsuits in the washer?

The milky could be whatever may be chewing up the bromine, or just air that is being introduced when the jets are on. The older the water the more noticable the air is by making it milky because the TDS is higher. Have you cleaned your filter recently? There are many things that can deplete the bromine, lets narrow them down and it will help, the big thing is not to use your tub if the reading is at zero.

[Kapp]

We have same situation. Using bromine tablets in floater. The only time I can get Bromine to register at all in when I shock it once a week. Then its off the charts for about 1 day then zero again and again. I know its in there and tabs. One person suggested our cloudy (Milky water when jets turned on) was due to too much bromine. I cut back to two tabs in the dipenser and opened to required level for our number of gallons. Now nothing, won't even show on test strips (unless I shock) yes we have an ozonator...in other words..I have no idea how much is really in there...too much or too little because I can't what I feel is a "true"reading. the other issue is still not solved (Milky water when jets turned on otherwise crystal clear, all chem levels except bromine show perfect) clears up in less then a minute to crystal clear. Its like pouring gallons of milk (from millions of tiny bubbles i guess) right into to tub when you turn on the jets and wondering if this in not Bromine level related. thanks

When you say your reading is sky high after a shock, how long are you waiting to test the water after shocking? You have to wait a while for the chems to do their work. If it is at zero the next day, you did not shock enough. Zero means there is something in the water chewing up the bromine. What is the spa usuage? You may need to super shock since the reading is dropping, indicating that you have not oxidized everything, and you may need to add shock once or twice during the week if you are using the tub daily. Did you start with sodium bromide to form a reserve? How long since your last water change? Are there metals in the water? Swimsuits? Are you putting swimsuits in the washer?

The milky could be whatever may be chewing up the bromine, or just air that is being introduced when the jets are on. The older the water the more noticable the air is by making it milky because the TDS is higher. Have you cleaned your filter recently? There are many things that can deplete the bromine, lets narrow them down and it will help, the big thing is not to use your tub if the reading is at zero.

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One dealer told me 20 mins so I have been doing that, then next day almost completely gone barely showing on strip, then then the next day 0. Shocking once a week (1 user about 4-5 times a week for 30 mins) No did not start with reserve, just put 6 tablets in floating dispenser. This is our first hot tub and we are on our first round of water started end of Oct so a little over 3 months. Our water here is high in calcium but readings of PH acid and calcium all in good range. I used one bottle of Metal Gon when filling it originally. I have added about a 10 gallon container of water 3 times to replace splashed out water and evaporation etc. with no further addition of any "metal gon" Yes swimsuits in washer. Never cleaned filters yet (the long way, taking them out soaking them overnight etc) Have taken them out once to rinse with hose and they all looked very clean, nothing came out or was visible. Thanks Kapp

[Hillbilly Hot Tub]

I am guessing you are not using enough shock to oxidize the wastes being introduced, thus using up the bromine quickly. Increase the amount/times of shock you do. You also need to clean your filters more frequently. the stuff that is trapped in them is also chewing up your bromine as the water passes through them. You will be surprised how much stuff the filter cleaning products pull out of the filters. With your spa use i would be cleaning them weekly and soaking them monthly. You may not be seeing stuff, but it is in there. Filters are the first most important step to sparkling clean water.

Here is a summary of bromine and how to maintain them:

Bromine

When bromine is added to a spa it's in the form of bromide ions. It then activated with an oxidizer to form hypobromous acid. Hypobromous acid is the killing form of bromine. When hypobromous acid reacts with an organic contaminant it's reduced back to bromide ions. The bromide ions can then be reactivated back into hypobromous acid by the addition of an oxidizer. This is somewhat of a continuos cycle with bromine sanitized spas.

If 100 percent of the bromide ions became hypobromous acid and 100 percent of the hypobromous acid returned to bromide ions, you would never again have to add more bromide salt. But hypobromous acid can react with certain chemicals in the water that tie up the bromide ions and prevents them from becoming free bromide ions in the water. This happens when hypobromous acid produces bromate or bromoform for instance. There are many other combinations that tie up the bromine so it can not become a free bromide ions. For this reason more bromine salt or bromide ions need to periodically be added. The level of bromide ions should not go below 15 ppm.

The basis behind 2-part liquid bromine sanitizing systems is to add a salt of bromine (sodium bromide) to the water to get bromide ions and then oxidize the bromide ions with an oxidizer such as monopersulfate (MPS), hydrogen peroxide, percarbonate, ozone or any compound of chlorine to produce hypobromous acid. You need a minimum of 15 ppm of bromide ions for an oxidizer to work and to provide a "bank" of bromide ions for an oxidizer to react with.

Bromine tablets are typically 1-bromo-3-chloro-5,5-dimethylhydantoin. When added to water they hydrolyze to become hypobromous acid. With bromine tablets a separate oxidizer is not necessary to make hypobromous acid, it is already an ingredient in the tablets. When the hypobromous acid reacts with a contaminant and is reduced, it becomes a bromide ion. You then get a build up of bromide ions in the water. After a while, you could just start adding an oxidizer to reactivate the bromide ions to hypobromous acid, but most people don't, they just add more bromine tabs.

Currently is no way to test water to find out how much bromide ions are in it. This is because the same test that measures bromide ions also measures chloride ions and all water has chloride ions in it. Other than making an educated guess, there's no way to tell when the bromide ion level is too low. The 2-part bromine manufacturers know this and recommend that you add some bromide ions (liquid bromide salts) every few weeks or so.

Realistically, a bromine sanitized spa can not be switched over to chlorine, if there's still bromine in the water. All the chlorine added to the water is going to convert bromide ions into hypobromous acid. As long as there's 15 ppm or more of bromide ions in the water, all the chlorine added is going towards converting bromide ions into hypobromous acid, none of it will provide a chlorine residual. The spa will continue to be bromine sanitized until the bromide level gets below 15 ppm. But there is no test kit for measuring just bromide ions in the water and therefore no way to know when the bromide level is below 15 ppm. It could take a week. It could take 2 months.

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Maintaining a Bromine Sanitized Spa

Upon initially filling, you need to establish a bromide ion reserve in the water. Bromine tablets can do this by themselves, but it can literally take weeks until enough tablets dissolve. Some people crush about 6 tablets up and put them in the water to achieve this initial reserve, but it's really easier and cheaper to add a packet or two of sodium bromide! Bromine tablets contain both bromine and chlorine to oxidize the bromine into active sanitizer. If you do not add the sodium bromide and just put in bromine tablets then you will be starting with a chlorine system until enough bromide dissolves in the water.

There are basically two types of bromine systems, 2-step and 3-step. In the 2-step system you add the sodium bromide to the water to the proper concentration, then add oxidizer on a regular basis (usually, chlorine, MPS, or ozone, or a combination of them) to oxidize the bromide ions into hypobromous acid, your active sanitizer. One of the more popular 2-step bromine systems is the Enhance/Activate Sanitizing System. It's quite easy but does require a bit of attention daily to maintain the bromine levels in the water.

A 3-step system is identical with the addition of bromine tablets in a floating feeder. This requires a bit less maintenance than the 2-step system, maintains a slightly more constant bromine level in the water, by allowing the bromine tablets to continuously and slowly dissolve into the water. The 3-step system costs more than the 2-step, since the bromine tablets are the most expensive part of this equation.

If you use the 2-step system and have an efficient ozonator, you might be able to achieve the constant bromine level without the use, or by using less oxidizer (MPS or chlorine) since the ozone is constantly oxidizing the sodium bromide while it is on. However, you may also deplete the bromide reserve more quickly this way, leading to the use of more sodium bromide, or a shorter time between drain and refills. Also, ozone can cause bromates to form in your water. Bromates are a suspected carcinogen in drinking water.

With either the 2-step or 3-step system you still need to shock the water, usually about once a week, to destroy organics in the water. "Shocking" involves raising the bromine levels to above 10 ppm. For shocking, any type of chlorine, or non-chlorine shock (MPS) can be used.

Simple Step by Step

Upon initially filling, balance the water (adjust TA and pH and calcium).

If you have metals in your water add a metal sequesterant.

On each fill add sodium bromide to the water (following manufacturer's directions on dosing, you'll end up with about a 30 ppm concentration of sodium bromide ions).

Shock with your preferred oxidizer (chlorine or MPS) and turn on the ozone if you are using it. Your bromine levels should be above 10 ppm (wait until they drop below 10 ppm to use spa).

If using a 3-step system add your floating feeder with bromine tablets and adjust it to maintain a 4-6 ppm bromine level. If using a 2-step system add your preferred oxidizer as needed (and adjust your ozone) to maintain a 4-6 ppm bromine level.

Shock weekly to burn off organics that collect in the water (if you are using ozone and your bromine levels are staying at 4-6 ppm then you may be able to shock less often).

Test bromine and pH each time you use the spa. Test all water parameters (bromine, pH, TA, Calcium Hardness) weekly.

Drain and refill about every 3-4 months.

If you shock and the reading is back to zero in less than 24 hours with no spa use, you did not use enough shock. Shock again until you can maintain a reading, then adjust your daily/weekly maintenance to allow for more shock to prevent this issue from happening.

[Susanj]

Very helpful thread!

I have a few ongoing problems with my spa. It’s an acrylic shell , 375 gallons and we use the 3 step bromide system. 

 

1.After one use I can get a bromine reading of 0 and I’ve even  waited overnight to see  if the floater  would bring it up like I expect it to , but no. I have to shock.  This doesn’t seem right.

 

2. I have trouble getting alkalinity over 40 especially without pH going too high . I read somewhere that even 40-50 can be ok? 

3. I had been shocking with MPS  . This spa is at my vacation rental and our service person suggested also using a bit of Dichlor since he was having trouble keeping the water crystal clear .  Any problems with this?