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Trouble with new spa chemistry


rocket04
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I just got a new jacuzzi and am having a bit of trouble with the chemistry. One issue I have is that I was sold a mix of sodium bromine and dichlor in granules and told I could just use that. But then after coming online I’m seeing posts about a bromide reserve and just using bleach in some places, in others it says use dichlor tablets. At this point, I still have a crapload of my granules and wondering if I can keep using that or should switch. It’s been a struggle keeping ph low enough, it’s rising all the time. Today, I added some granules and turned on the jets and there was quite a bit of foam, and I also noticed the water is cloudy. I suspect I may not have been using enough sanitizer, but not sure. Here are my latest test results, obtained with a Taylor kit. Only thing I don’t have is FC because it keeps dropping quite fast and by the time I test it’s usually 0 until I dump more bromine/dichlor in:

ph: 7.7

TA: 110

Ch: 170

CYA: 60

 

 Any help is appreciated. I just keep reading that spa water can go south much faster than water and you sometimes have to empty and restart. Given that it’s already freezing here, I’d rather not have to do that. 

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Well, for starters, we recommend ahhsome spa purge for all new spas. All kinds of nasties grow in those pipes between wet test at the factory and delivery to your house. You have to drain after use, so get some before you drain it.

Sodium bromide creates the bromide bank or reserve. It is then oxidized into bromine with chlorine or mps. Only then will it be readable on a test. You are testing bromine, not chlorine, even though you are adding chlorine. As bromine does it's thing it (mostly) reverts back to bromide. 

Dichlor is almost half cya. Cya over 30ppm begins to lock up some chlorine, requiring a higher chlorine use to accomplish the same level of sanitation. I am not clear on how this affects bromide oxidation. 

Aeration causes ph rise, so close the air control valves when not in use. 

Chlorine and bromine use the same test, but bromine reads double chlorine. The fact that you get no reading after adding chlorine indicates a contaminant buildup that is using your bromine/chlorine as fast as you are adding it. 

@waterbear, @Ahhsomeguy, anything to add?

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On 11/27/2021 at 8:28 PM, rocket04 said:

. One issue I have is that I was sold a mix of sodium bromine and dichlor in granules and told I could just use that.

You can, Eventually it will build up a bromide bank. Until it does you have a chlorine spa. The transition is nothing you have to worry about as long as you are keeping your sanitizer at the correct level (4 to 6 ppm) You  are in Canada so you cannot get sodium bromide, it's been outlawed, so if you want to run bromine your choices are a one step product like you are using or using bromine tabs in a floater or using both together. In a few weeks there will be enough bromide in the water and you will no longer have chlorine, you will have bromine. Just keep the sanitizer in the 4 to 6 ppm range and don't loose any sleep over it.

https://www.poolspaforum.com/forum/index.php?/topic/53410-how-to-use-bromine-3-step-method/

 

On 11/27/2021 at 8:28 PM, rocket04 said:

... using bleach in some places, in others it says use dichlor tablets.

You are confusing the dichlor/bleach method (chlorine spa) with 3 step bromine (bromine spa). DIchlor really is not a problem with bromine as it can be with chlorine because of stabilizer buildup over time. DIchlor is a granular, fast dissolving organic chlorine source. Trichlor is a slow dissolving organic chlorine source in tablet form and not recommended for spas and hot tubs because of it's very low pH. Both trichlor and dichlor add CYA (stabilizer) to the water and build up over time (for dichlor it's pretty fast). Once the CYA gets high the chlorine becomes less effective at sanitizing and oxidizing and the water starts having problems. However, some CYA is necessary in a chlorine  tub or pool. The solution is to switch to an inorganic chlorine source such as bleach (liquid pool chlorine, Sodium Hypochlorite), Calcium Hypochlorite or cal hypo, Lithium Hypochlorite once the CYA reaches the desired level, usually about 30 ppm. These do not contain CYA so they will not cause it to continue rising.  Both calcium and lithium hypochlorite are granular products. Lithium hypo is very expensive but has no other drawbacks, CAl hypo will cause calcium hardness to climb so it can be problematic. Sodium hypochlorite is liquid, inexpensive, and effective. You might know it as liquid laundry bleach. FWIW, ANY of these chlorine sources can be used to oxidize a bromide bank into bromine sanitizer. one step bromine products such as you have are mostly dichlor with a small amount of sodium bromide and bromine tabs are mostly chlorine/Dimethylhydantoin conpounds with a small amount of bromine/Dimethylhydantoin compunds. Once again the chlorine oxidizes the bromine compound to form active bromine sanitizer (hypobromous acid.)

 

 

 

On 11/27/2021 at 8:28 PM, rocket04 said:

It’s been a struggle keeping ph low enough, it’s rising all the time.

Your TA is WAY too high at 110 ppm. Lower it to 50 to 70 ppm and keep your pH around 7.7 and you will have much better pH stability.

https://www.poolspaforum.com/forum/index.php?/topic/52522-some-truths-about-ph-and-ta/

https://www.poolspaforum.com/forum/index.php?/topic/28846-lowering-total-alkalinity-howto/

 

On 11/27/2021 at 8:28 PM, rocket04 said:

Here are my latest test results, obtained with a Taylor kit. Only thing I don’t have is FC because it keeps dropping quite fast and by the time I test it’s usually 0 until I dump more bromine/dichlor in:

ph: 7.7

TA: 110

Ch: 170

CYA: 60

Which Taylor test kit do you have?

First, you are running a bromine spa so ignore CYA, it has no effect on bromine. Your pH is fine, bromine is effective over a wide pH range (7.2 to 8.0) If your test kit has a specific test for bromine or has a bromine scale on the comparator block use it and ignore the chlorine scale. If it only has a chlorine scale or test only do the test for free chlorine and multiply the results by 2.25 to get the total bromine reading (just doubling the chlorine reading is close enough so make it easy on yourself). CH is fine. You want enough hardness to help prevent foaming but not so much that you will have a tendency to scale. 130 to 200 PPM is fine.

If your sanitizer is not holding then something is consuming it (purge the spa) or you are not adding enough or adding it often enough to maintain your bromine level in the correct range (add sanitizer daily and make sure you are adding enough, You might want to consider adding a floater with bromine tablets and adjust it to maintain the bromine level in the 4 to 6 ppm range, also shock weekly with chlorine, either dichlor or bleach (not your one step bromine sanitizer which is a mixture of dichlor and sodium bromide) , You want to add enough to raise the sanitizer above 10 ppm. with the spa running and uncovered. Wait for the sanitizer to drop to 10 ppm or lower before entering or covering. Do this weekly as part of your normal maintenance..

 

On 11/27/2021 at 8:28 PM, rocket04 said:

Today, I added some granules and turned on the jets and there was quite a bit of foam, and I also noticed the water is cloudy. I suspect I may not have been using enough sanitizer, but not sure.

most likely or you might have biofilm in the plumbing and need to purge the spa. New spas are water tested by the manufacturers and the water left inside often breeds biofilm.

 If maintaining the sanitizer in the correct 4 to 6 ppm total bromine and weekly shocking don't solve the problem then you should consider purging the spa.

 

 

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  Firstly, thanks a lot for the detailed answer. I'm feeling much better already. You make that kind of investment in something, last thing you need is for things to go to **** in the first two weeks!

12 hours ago, waterbear said:

You can, Eventually it will build up a bromide bank. Until it does you have a chlorine spa. The transition is nothing you have to worry about as long as you are keeping your sanitizer at the correct level (4 to 6 ppm) You  are in Canada so you cannot get sodium bromide, it's been outlawed, so if you want to run bromine your choices are a one step product like you are using or using bromine tabs in a floater or using both together. In a few weeks there will be enough bromide in the water and you will no longer have chlorine, you will have bromine. Just keep the sanitizer in the 4 to 6 ppm range and don't loose any sleep over it.

https://www.poolspaforum.com/forum/index.php?/topic/53410-how-to-use-bromine-3-step-method/

OK, in all likelihood that was my problem, I didn't keep the chlorine level high enough in the first couple weeks (i'm going on third week now) and so the chlorine level was getting low very fast even though it got super high after I put a few scoops of granules in it. Now that it's been a few weeks and in the past days I made sure to put more granules more often, it seems like FC is getting more stable.

 

12 hours ago, waterbear said:

Your TA is WAY too high at 110 ppm. Lower it to 50 to 70 ppm and keep your pH around 7.7 and you will have much better pH stability.

https://www.poolspaforum.com/forum/index.php?/topic/52522-some-truths-about-ph-and-ta/

https://www.poolspaforum.com/forum/index.php?/topic/28846-lowering-total-alkalinity-howto/

That's good to know. I was trying to follow the recommendations in the manual that state 100-150pm are optimal levels. I'll look into lowering it if pH doesn't stabilize, it's been a bit better lately, it rises a bit, but not the wild swings I was getting before.

12 hours ago, waterbear said:

Which Taylor test kit do you have?

I have the K-2006 with FAS_DPD, so not the Bromine one. I did read about multiplying by 2.25 for Bromine so that's what I've been doing. One thing I'm still not sure of, is there a way to know that I've built that bromide bank? And once built, I assume it will get depleted, but is it at a pretty slow rate? Could I just use a floater most of the time and then once in a while drop some of my granule solution instead to add some sodium bromide?

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11 hours ago, rocket04 said:

I didn't keep the chlorine level high enough in the first couple weeks

You are running bromine, not chlorine. Even if you add just chlorine to a bromine system it will convert to bromine.Think in terms of bromine, not chlorine, even if the bromide bank has not built up after a fresh fill. It will make your life easier.

 

11 hours ago, rocket04 said:

I made sure to put more granules more often

How often were you adding the one step bromine product to your spa? Usually, if you are not using a floater with tabs, you need to dose every day to every other day so you maintain a constant sanitizer level. Adding a floater and adjusting it to maintain the sanitizer at a constant level will make life easier and yo will not need to does as often. I wold recommend weekly shocking with the granular product in that case.

 

11 hours ago, rocket04 said:

I'll look into lowering it if pH doesn't stabilize

It probably won't. Reread the links I posted and lower your TA.

 

11 hours ago, rocket04 said:

have the K-2006

Test FC and multiply the results by 2.25 to get total bromine. No need to test for CC, not applicable. Also, no need to test CYA, not applicable to bromine. In fact, the CYA test is not included in the Taylor K-22106 FAS-DPD test kit for bromine along with the reagent for testing CC. The TA and CH tests are identical in both kits.

 

11 hours ago, rocket04 said:

One thing I'm still not sure of, is there a way to know that I've built that bromide bank?

Don't worry about it. Just maintain your santizer in the 4 to 6 ppm range and test as if the bromide bank is there. It will be in a short time.

 

11 hours ago, rocket04 said:

I assume it will get depleted, but is it at a pretty slow rate?

If you have ozone or UV it could get oxidized to bromate, which is an undesired oxidation product that won't convert into hypobroumous acid, which is your acitve bromine sanitizer. IF you are draining and refilling every 3 to 4 months as recommended it's a non issue, even with ozone/UV.

 

11 hours ago, rocket04 said:

Could I just use a floater most of the time and then once in a while drop some of my granule solution instead to add some sodium bromide?

Tablets in a floater will also contribute to the bromide bank. As I said earlier, a floater will make your maintenance a bit easier once you get the floater adjusted properly to maintain your sanitizer level.. Use the granular product weekly to shock (raise the bromine to above 10 ppm.)

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