Bromine Vs. Chlorine Questions; Seldom Used Spa

[mrwrick]

I am a relative newbie. I have had great advice here getting my used spa up to running condition and thank all here. Now I am dealing with startup issues over how to sanitize and maintain the water. The Water Chemistry forum has more great information about the how-to. I am ready to follow the steps for the method I choose. My question is: What is the difference between using chlorine vs. bromine as a sanitation medium in a spa that sits idle for weeks at a time? Are there downside issues with either? My spa is a 20 year old HotSpring spa, a Classic "dog bowl" style well suited to me and my wife and friends. It has sat unused for 3 years while i dealt with moving issues and then slow deck construction (another story) and is finally in place, cleaned, ready to be filled, flushed, drained and refilled with new filters and a new sanitation system. We are infrequently at the house where the tub is. It is a vacation property. So, maintenance, testing and water treatment will be done only as often as once or twice a month for a few days each trip. We are on well water with high levels of iron, no filtration, although I bought a SpaStick for the hose. So, what can you tell me about the pros and cons of bromine vs. Chlorine and what do you recommend for sanitation? Thanks to all.

[chem geek]

Chlorine won't work in your situation since you need to add it regularly unless you have a saltwater chlorine generator. With bromine, you can have a bromine floater that will last a week or so, but probably won't last for as long as you need only tending to the spa once or twice a month. Do you have an ozonator? With a small bromide bank, it's possible that you could have it maintain a bromine level consistently, but that is tricky to do for such an extended time between visits.

[mrwrick]

Thanks Chem Geek. Can you guide me to start research on an ozonator for a 1993 Hot Spring Classic?

[chem geek]

You might search for ozonators at Backyard Plus which seems to have parts for Hot Spring spas, but I'm sure others will have suggestions for other sources. I don't think an ozonator installation is something a spa owner is supposed to do -- it may require a spa dealer technician to come out unless you are quite handy with such installations. You'd want to be able to dial down it's "on-time", possibly with the circulation pump time, so that it doesn't output too much ozone per day so that it doesn't create too much bromine per day.

I did mention that you could use a saltwater chlorine generator such as the ControlOMatic Technichlor, but it doesn't have any feedback measurement so you'd have to carefully experiment to see what output level would maintain a constant level of chlorine and it may be that you couldn't turn it down enough since I presume you'll probably turn down the temperature of the spa (perhaps to 80ºF or so) in between your visits.

Either technique (ozonator with bromide bank or saltwater chlorine generator) is dicey because there is no measurement feedback to control the bromine or chlorine level. You have to manually determine that. Fortunately, the way chlorine and bromine get used/consumed, there is a negative feedback loop in that they fall off as a percentage of their level. So the ozonator or saltwater chlorine generator will raise the bromine or chlorine level, respectively, but it won't go up forever and will instead rise to a level where it's usage which is a percentage of its level equals the absolute amount generated. However, there is still the risk of the pH rising to the point where you get calcium carbonate scaling because you won't be around to monitor it (the use of 50 ppm Borates, say from boric acid, can lessen the pH rise, but won't eliminate it).

Another possibility for you would be to try "alternative" products to keep the spa in decent shape between soaks, but these have risks of failure associated with them. Copper/silver combination ionization is a possibility as are certain surfactant and enzyme systems. These are the ones that claim to let you go without chlorine or bromine. Though that doesn't work well with spa use due to bather waste and they do not kill quickly enough to pass EPA DIS/TSS-12, they might prevent the spa from going bad between your visits. Again, it's risky because they may not work. Generally, such systems do prevent uncontrolled bacterial growth and some prevent biofilm formation. You could always shock the spa when you arrive and if you want to get in soon then you can use hydrogen peroxide to quickly lower the disinfectant level (but not to zero) just before your soak. In this case, a chlorine system at least when you are tending to the spa is likely to work best.

For a copper/silver system, something like Carefree, SpaRx, rhtubs or Almost Heaven might work. I don't want to recommend Nature² which uses only silver ions (and non-chlorine shock, but that probably won't last a month and is supposed to be used at hot spa temperatuers) because silver ions alone won't prevent Legionella pneumophila (used with non-chlorine shock, Nature² is OK, but silver ions alone are not). Copper does well with that while the silver handles fecal bacteria. This post shows kill times for chlorine, copper and silver. So a copper/silver combo should be good enough to prevent uncontrolled bacterial growth for a reasonably large variety of bacteria. The main risk is that of metal staining if you overdose or the pH gets too high.

For a surfactant-based product that disrupts biofilm formation, Aquafinesse would be reasonable. They say to add it once a week, but it might last longer in a spa that is cooler (80ºF) and not used. However, I don't know of any studies of using the product alone without chlorine/bromine so don't know if it is good against a wide variety of bacteria that may be found in spas. I know that people who have tried using "alternative" products to chlorine and bromine have had a higher incidence of hot tub rash/itch/lung reported on this forum. Then again, those using chlorine/bromine who did not dose enough so let such levels get to zero also reported problems and those using Dichlor-only for many months building up high CYA levels also had a higher incidence of problems (but sample sizes were small so it's not definitive).

The key to using either of the above product types is that you will be shocking with chlorine when you arrive and you will be adding sufficient chlorine after each spa use to handle your bather waste. You will be protected during your soak not only by the aforementioned products, but also by the small amount of chlorine at the start of your soak. While not guaranteed to work, this does sound like the best approach for your situation though someone else may come up with something better.

[des]

In a similar situation as the original poster, I see that a 3-

step bromine based system with an ozone generator is the

recommended way to go. I am ready to start here and have a copy

of waterbear's directions as well as dlleno's ozone-utilizing post.

We will usually have 3 people on weekend soaks with times of 2-3

week absences. Perhaps since the time of this post, there are

now bromine-generating salt systems like Blu Fusion here:

http://bluwatertechnology.com/systems/isis/ . Are they just

using a fancy ozone generator? I can't find any info on the

boards. Would it keep the bromine level more stable than just a

basic ozone generator? They make many great claims on their

website like only changing water once a year.

Any experiences you can share would be helpful. I have sensitive

skin (including to many soaps, lotions, and SLS), allergies (not

known to spa specific chemicals), eczema, and allergy-related

asthma. I would rather not go through a "test everything to see

if you react", and prefer to start with a system I am less

likely to react to. My spa store suggested starting with

bromine, so I have granules. I have already disinfected my

Jacuzzi J345 spa that came with my house and am ready to refill

and begin. I do NOT yet have an ozone-generator, so I would either add one, or add something like the Blu Fusion mentioned above.

Thank you for this forum and for any advice you can offer.

[SpeedAddict]

A quick bump on des's question about the brome generator ... an interesting question for the cottage spa.

[chem geek]

A bromine generator converts sodium bromide to bromine via electrolysis. An ozonator converts bromide to bromine via oxidation though ozone also breaks down bromine to bromate. So over time you need to increase the bromide bank if you use an ozonator. Most people use bromine tabs to do that and to provide some additional bromine.

So if you want the most "pure" bromine experience then using the bromide salt-based bromine generator would be the way to go. Not all spas are designed to withstand the higher corrosion potential from the higher salt levels needed for a bromine generator.

Note that the most common bromine tabs, BCDMH, have both chlorine and bromine though the bromine doesn't last long in a spa with a bromide bank since the chlorine oxidizes bromide to bromine. There are bromine-only tabs, DBCMH, but they are less common. If you use chlorine as your oxidizer, then again chlorine will briefly be present. So the only way to avoid chlorine at all times would be to use MPS (monopersulfate non-chlorine shock) as the oxidizer, but some people have skin sensitive to MPS. If you use chlorine only after your soak after you get out, then there shouldn't be any chlorine left after a short time.

So it's up to you which way to go. Unless you use chlorine shortly before your soak, you should not be exposed to chlorine unless you use the more common BCDMH tabs.

Note that many people with skin issues actually do better with chlorine. To switch from a bromine to a chlorine spa you would need to change the water. To go from chlorine to bromine, you just add a bromide bank and you are then a bromine spa (and can add bromine tabs if desired).

[SpeedAddict]

Thanks for the answer. I bought a Cottage that came with a spa, so I'm a total newbie as for spa maintenance.

[mrwrick]

SO, finally, here I am with a full spa tub, 325 gallons, a working 24/7 low speed circulation pump and a working new Del Ozone generator. I have experienced somewhat high initial TA, 140 ppm, and high initial pH, 8.0 in Taylor test kit. Acid Demand Test called for 4 test drops to reduce pH to 7.2. I added 3.6 teaspoons of Muriatic Acid in liquid form mixed with spa water in 4 decreasing volume increments over 4 days, according to the Taylor Treatment Tables and conversion tables for volume, 50% of acid, 25% of acid, 15% and 10%. The pH gradually and predictably decreased from a pink 8.0 to slightly orange 7.4. I added 2 oz. sodium bromide to establish a bromide bank and put in a tablet floater. On the fifth day I tested pH and was surprised to see pink again, 8.0. Acid demand again called for multiple drops, 3 this time, so i added the first 50% increment only and retested the 6th day, still high pH without discernible change downward. What is happening? Is combination of 24/7 ozone and bromine increasing pH or giving me a false high due to other chemical interaction obscuring the true pH test reaction? Thanks

[chem geek]

The problem you are having is that your TA is too high so with the ozonator creating air bubbles you have a lot of carbon dioxide outgassing and that causes the pH to rise. You can minimize this by lowering your TA level. If the pH rise is still too high with a TA of 70 or 80 ppm, then you can lower the TA to 50 ppm and add 50 ppm Borates (usually from boric acid).

As for chemical reaction with the pH test, if the bromine level is very high (above around 20 ppm or so) then that can bleach out the pH test, but since you do sometimes measure the pH as lower I think your pH test is correct. What you are seeing is an actual pH rise that is explained from the higher TA.

[mrwrick]

Thanks. I will work on the TA level. Is there a thread here that discusses the process? I know too much acid can cause corrosion. so I was reluctant to start adding more Muriatic acid again before I found out why the last treatment failed to show a correct test.

[mrwrick]

I found it, right at the beginning of the forum section. Thanks. As usual, the rule is "pay attention."

[mrwrick]

Back again. Finally got the right relay installed for the heater, so the spa is working fine now. So the system has the 24/7 recirc pump and Del Ozone generator, also working 24/7. I get pH in the 8.0 range, pink to purple color on Taylor kit reagent test. The TA came out at 70 today, so that's better than when I first started the bromine system with bromide bank and floater, same time as ozonator got working

. How am I doing so far?

[mrwrick]

Further to my update, the spa was filled 2 months ago, water was super chlorinated, then sodium bromide added for bromide bank. The pH was high, also TA, at 140. It was steady at 70 degrees, no heater yet, now working. The spa has sat being filtered and ozone tend with bromine tabs in floater since late February, water clear, good strong bromine level, no bather load, just a few bugs hand removed. Now that heater is working with the filtration and ozonation I get TA of 70 but pH still showing high on Taylor scale, bright pink. Do I understand that the ozone may contribute to high pH? It runs 24/7 tied to the recirculation pump. Does the OK level of TA mean pH is not being truly indicated by color? I read that the color may be being bleached by other factors. I am very pleased with capacity of the sanitation to be maintained during absences of 2 or more weeks. I know that heat reduces effectiveness and life of chlorine. Does bromine react similarly? I am keeping spa thermostat turned way down while away to save power usage

/utility bill. Other than the cost of electricity and evaporation is there a downside for sanitation of the bromine spa if I leave heat up? Thanks for leading me by the hand on this.

[mrwrick]

I forgot to say I think I understand that my staged additions of liquid Muriatic acid a few weeks ago calculated by the Taylor test reagent Acid Demand test are the reason my TA dropped by half from 140 to 70, a good result. Do I need to worry about pH test or just keep on top of TA since the pH is being affected by other factors, such as continual ozone addition and the aeration?

[chem geek]

If your pH is rising over time, then lower your TA. A high TA will usually result in the pH rising especially in a hot spa with aeration unless you are using a lot of net acidic chemicals.

[mrwrick]

Only chemicals being used are ozone and bromine. I will add borates to lower TA and see how that does. Thanks

[chem geek]

To lower the TA, you have to add acid and aerate the water. You only add the borates AFTER you've lowered the TA.