Help with Bromine Level & Foam?

[RonPVa]

Hopefully someone can help me out with my foaming and loss of bromine problems with my 3-month old, 400 gallon spa (with an ozonator). I'm new to spa maintenance and am trying to get the hang of the bromine system (I've read lots of posts here & have the Taylor test kit and book).

I'm using a bromide salt/oxidizer one-step system (described in the Taylor book as dichlor with sodium bromide) as a bromine source - its the only bromine source I can find locally. After balancing the water I add the prescribed amount of the bromide/oxidizer solution, which drives the bromine to a high level. After a couple hours the bromine level reads good and all seems well. The next day, without any bather load, the bromine is gone. I then add MPS shock and the bromine level is back up, but its gone again the next day without any bather load.

The bromide/oxidizer bottle says to use it for both bromine level and shock, but this seemed like it would lead to excessive bromide levels, so I've been using the MPS for shock. (The spa vendor manual says to not use Clorine-based shock.)

After using the spa I add more shock as prescribed here. After about a week of use perhaps every other day (and lots of shocking to get the bromine level up) we get a lot of foaming when running the jets. The foam leaves a light-brownish residue on the sides of the spa. I rinse off the filter a couple times a week but don't notice a difference in foam generation.

I've dumped and refilled 2X trying to get rid of the foam.

Any ideas on what could be causing the loss of bromine or the foam/browning residue? Or anything else I am doing wrong?

Thanks in advance for any help,
Ron Pagano

 

[chem geek]

Welcome to TFP!

You shouldn't be losing so much bromine when there is no bather load, especially if your bromide bank is sufficient and your ozonator is working. The ozonator should be able to generate more bromine in addition to oxidizing bather waste (when you use the spa). You should make sure your ozonator is working and if you have an adjustment for its on-time you should turn that up. Maybe you just didn't add enough sodium bromide initially. See Using Bromine in a Spa for more info.

As for foaming, you can raise your Calcium Hardness (CH) level to 120-150 ppm to see if that helps, but make sure your pH doesn't get too high -- keep it at 7.8 or less. As for oxidizing the bromide to bromine, you can use bleach instead of Dichlor for that purpose, at least part of the time since it's more pH neutral and less expensive -- just make sure your TA is lower (probably 60-70 ppm, but as low as 50 ppm, if necessary) so that the pH doesn't rise too quickly.

You might need to decontaminate your spa -- it could have biofilms in the piping if you've never cleaned them. You can use Spa System Flush just before your next drain, then superchlorinate, then drain/refill (full procedure for the superchlorination part is in this post).

 

[RonPVa]

Thanks for the help! It does seem like I need to decontaminate my spa, so I've ordered the Spa System Flush and some sodium bromide for the re-start. Do I also need to do the 100 PPM superchlorination in addition to the Spa System Flush?
Also, when I mentioned using bleach to the spa vendor they strongly recommended against using bleach at all (although it didn't sound like they were too familiar with the chemistry involved and had ever heard of using bleach). Do you know of any spa components (seals, metal jets, etc) that could get harmed by using the bleach in place of the MPS?

 

[chem geek]

If you are super-chlorinating with the same water that had bromide in it, then just go to 50 ppm instead of 100 ppm.

Bleach will not harm components since it will oxidize the bromide to bromine assuming you initially set up a bromide bank. If you want to use Dichlor instead of bleach, you can, but it's more expensive though still less expensive than using MPS. Up to you since it's just a cost difference though if you use just MPS you may not have the water be as clear since it doesn't oxidize the same things chlorine does.

 

[RonPVa]

Thanks again. Just one more question, do I do the spa system flush, then drain and refill, then superchlorinate, then drain and refill? Or can I do the flush and then superchlorinate without draining and refilling in between?

 

[chem geek]

You can superchlorinate after you Spa System Flush without changing the water (wait for the time indicated in the Spa System Flush instructions). They don't interfere with each other except the superchlorination might break down some of the Spa System Flush, but that's OK after it's done its job removing biofilm from surfaces. However if the Spa System Flush results in a huge amount of junk to remove from the spa, then it might be best to dump that water first. So use your judgement.

 

[RonPVa]

Thanks much for your advice. I did the Spa System Flush, refilled and am using the bleach technique successfully to maintain bromine levels. I can now maintain bromine levels for several days and the water is clear with no foam!

Now I am having trouble keeping the water balanced (TA and pH levels). I set the TA and CH within the recommended ranges (CH=200, TA=90) and can't keep the pH down. It seems it needs more acid several days in a row (even without bathing) and then I check the TA and its way down to 40!

Any guidance on what I'm doing wrong? Do the water balance techniques described in the "How do I use Chlorine in my Spa (or pool)?" note also apply to a bromine tub? Should I also use borates to help buffer the pH?

Thanks,
Ron

 

[chem geek]

If you aren't using bromine tabs, then you may need to keep your TA lower around 50 ppm similar to what Dichlor-then-bleach users do. If you are using bromine tabs, then they are net acidic so usually you have the TA be somewhat higher but the basic rule is if the pH tends to rise over time then let the TA be lower (though not much below 50 ppm). If the pH is still rising too much at a low TA, you can consider using 50 ppm Borates if you don't have that in the water already.