Hot Tub Care Tips from Bob Lowry: Keep Your Spa Sparkling

Your hot tub can look crystal clear and still be one soak away from smelling “off.” We dig into the real reasons spa water goes sideways and what to do about it, starting with the question everyone asks: bromine vs chlorine. We talk through what bromine is great at in hot water, why bromamines don’t stink the way chloramines do, and the big catch that trips up most owners and techs: bromine disinfects, but it doesn’t oxidize the gunk we bring in on our skin.

From there we get specific about spa water chemistry and routines that actually work. We explain why sanitizer levels crash so fast in a 250 to 400 gallon hot tub, how bather load drives chlorine demand, and why “set it and forget it” usually fails unless you pair a steady feed with smart shocking. We also cover modern options like frog-style systems that add chlorine without cyanuric acid buildup, plus straight talk on liquid chlorine in spas and the industry myth that you can’t use it to shock a bromine tub.

We also break down UV sanitizer and ozone generators with real-world expectations. UV only treats what passes near the bulb and can lose effectiveness when the sleeve gets dirty, and ozone is powerful but short-lived, often working only near the return. The takeaway is simple: UV and ozone can help, but they don’t replace a residual sanitizer needed for person-to-person protection. Finally, we make draining non-negotiable, including the classic 90-day guideline and an easy bather-load way to decide when old water needs to go.

•Bromine strengths in hot water and higher pH
•Why bromine needs a separate oxidizer
•Post-soak shocking habits that prevent odor
•How fast chlorine or bromine gets used in a spa
•Frog-style systems as a low-CYA option
•Liquid chlorine in spas and the pH myth
•Why “don’t mix bromine and chlorine” is wrong
•UV limits due to contact time and dirty sleeves
•Ozone’s short lifespan and how to smell-check returns
•Drain schedules based on 90 days or bather load math

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Transcript

romine Vs Chlorine Basics

SPEAKER_01 1:21

Are you a full service pro looking to take your business to the next level? Join the Full Guide Coaching Program. Get expert advice, business tips, exclusive content, and get direct support from me. I'm a 35-year veteran in the industry. Whether you're starting out or scaling up, I've got the tools to help you succeed. Learn more at swimmingfullearning.com. Let's finish up here. We'll talk about spas and hot tubs. And so there's this big debate about bromine versus chlorine and hot tubs. There's so many different ways to sanitize a spa. The newer ones have UV and ozone built into them. So what would be the best sanitizer for a spa in your opinion? Bromine, chlorine, ozone, UV, you know?

romine Strengths And Weak Spots

hocking After Every Soak

ow Fast Sanitizer Gets Used

rog System And Liquid Chlorine

SPEAKER_02 2:05

Well, I think each of the each of the available disinfectants have their own characteristics that you end up having to deal with. And for many years, a lot of people used sodium dichlor or they used bromine tablets. And again, the bromine tablets were a convenient way to just put the thing in a feeder and and let it feed the right amount of bromine to the spot. There was some advantages to using bromine. And the advantages are that it works at a higher temperature, it works at a higher pH. Bromamines, which are bromine and ammonia getting together, don't smell, and there are active sanites. So it had those advantages. The disadvantage to bromine is that it is not an oxidizer. So it will kill things, it will kill bacteria, and it will kill algae, and it's pretty handy at doing that. But it doesn't oxidize sunblock, sweat, urine, soap, deodorant, airspray, you know, lotions, powders, those kinds of things that we have on our bodies. It doesn't oxidize those. We end up needing a separate oxidizer. But there isn't a test to determine when you need an oxidizer. So you have to guess at it. So you use the tablets and then you guess at how often you need to add an oxidizer. And that can be once or twice a week. One of the advice that I used to give people with a spa is every time you get out of the spa, add an ounce of oxidizer back to the spa. A non-chlorine shock. Add an oxidizer to the spa. When you get out, leave the spa on for 10 minutes and turn it off. And that way you will take care of most of the contamination that you brought in with you. And if you don't, then a couple of days later your spa's gonna kind of smell and stuff, and it's because the bromine can't kill that stuff, it can't oxidize it. So you need to add either a chlorine shock or a non-chlorine shock whenever you get out. And so you can use bromine, but as I've said, with with a spawn particular, the chlorine level, the sanitizer level goes to zero very quickly. And 265 gallons of water, one gram of chlorine is one part per million. And so it's it's a very small amount of chlorine to get a part per million. You're talking about a teaspoon providing four or five parts per million of chlorine. By the same token, a a person has a a chlorine demand of about four grams of chlorine. So when they get in the spa, I've often said two people in a 400-gallon spa will use up one part per million of chlorine in 15 minutes. And and use up two parts per million of bromine in 15 minutes. So the chlorine level can disappear 15 minutes after you put it in. So it's important that we have something that supplies that chlorine back, or that the homeowner is supplementing it either with adding some dichlor or some oxidizer when they get out, and then let the bromine do its job. I don't think it's an either-or, it's a matter of which one works best for you. The frog system that they've just come out with is a is essentially the same as a as a bromine tab, except they put chlorine with it. And so it is a tablet of chlorine, but it doesn't have any cyanuric acid in it. So it's a pretty cool system because it's chlorine without adding cyanuric acid to the to the spa. So it's a a viable alternative to bromine or using dichlorine there.

SPEAKER_01 6:54

What about liquid chlorine? I know a lot of people use liquid chlorine in spas.

SPEAKER_02 6:58

You can you can use liquid chlorine in a spa, no problem. Um again, the people that say you shouldn't are the people that still believe when you add liquid chlorine, it raises the pH. And and we now know that liquid chlorine doesn't raise the pH. So there's there's less of a reason to not use it.

ebunking The Mixing Myth

SPEAKER_01 7:19

What about the I hear this all the time, and I've heard it since I started the industry that you shouldn't mix in a spa bromine tablets, and then you shouldn't use liquid chlorine to shock the spa. There's something kind of some kind of reaction with that, or is that just something that's developed? It's one of those myths in the industry.

SPEAKER_02 7:36

It's a myth. It's a myth. But you know, you need if you're using bromine tabs in a spa, you need to periodically shock it. And you can, it's your choice what you want to shock it with. You can shock it with liquid chlorine, you can shock it with dichlor, you can shock it with callico, you can shock it with monoplysulfate or a non-chlorine shock, or even hydrogen peroxide.

SPEAKER_01 8:04

What about like the UV and ozones that are coming with the newer spas? Do you think those are good methods? I know people think that having the UV and ozone means they don't need chlorine in their spa, which is not true, right?

SPEAKER_02 8:15

That is absolutely not true. Okay, and and part of the biggest reason, which I said earlier today, was from beta to beter transmission. And think about this. UV, the only thing that is the only things that are being killed or changed are things that are passing within one inch of that UV vault. So anything that's in the spa that's attached or too big to get into the the system, it's not seeing the UV. So if you have a biofilm growing, if you have algae growing or whatever, it's not going through where the UV is. So it only kills stuff going through it. And the UV system, the the bulb is usually inside of a an optically clear sleeve. And if that sleeve gets dirty from soap, oil, calcium, magnesium, whatever, if it gets a deposit or it gets soap film or something on it, it changes the optics of that that glass sleeve, and you no longer are putting out the proper wavelength to get rid of anything. The the proper wavelength to kill things with UV is 254 nanometers. And if you make that sleeve dirty, it's no longer outputting at 254 nanometers, which means it's not killing anything. So if it gets dirty, it's not killing anything. Ozone is very powerful stuff, it can be up to 2,000 times more powerful than chlorine. But it only exists in water under good conditions, under great conditions, for between three and 15 minutes. That's it. So three to 15 minutes, and most of the time, especially in a spa, the ozone lasts for seconds. So and and you can prove that by actually sticking your nose as close as you can to a return line. And if you can't smell ozone in that return, then you probably don't have any ozone getting into the spa. And oxidation is being done within literally a few inches of the ozonator.

SPEAKER_01 11:27

And the smell of that, what is that, Bob?

ow To Tell If Ozone Works

SPEAKER_02 11:28

When you smell it, you say people have have likened the smell of ozone to either wet hay. Some people never get near hay, around a when there is a thunderstorm, you can kind of smell the ionization in the air a little bit. The other place that most people might remember it is if they've ever stood by a photocopy machine and made 50 copies. That smell that comes out of there is not a not the toner smell, you're smelling ozone.

SPEAKER_01 12:05

Huh, interesting. I never thought about smelling it, but that's that's a good point. At all my hot tubs, I I keep a submersible pump behind it. I tell the customer, I'm leaving this pump here because I'm going to be draining your spot every three or four months. And I think that's one thing that a lot of people neglect is this water is in here. It's like a bathtub kind of, and you're just chemicalizing it. It needs to be drained often, right? Yes, yes.

rain Schedules That Actually Work

SPEAKER_02 12:33

I I recommended for years that you drain your spa every 90 days. I was on the committee that created a drain routine for at the time NSPI for commercial spas. And you take one-third of the gallons in the spa divided by a bather loaf. And the resulting answer is how many days you can use the water. And and it actually works in a for a homeowner spa, if you think about it, you've got what 250 gallons, 350 gallons, 350 gallons, a third of that's 110. If you divide two people into 110, you can use the water for 55 days. Yeah, smart.

SPEAKER_01 13:18

I think that's one equation that a lot of people are struggling with when they have their hot tub and they're in they're doing pool service and they can't clear it up or they can't figure out what's wrong with it. The simple answer is you have to be you have to drain it.

SPEAKER_02 13:30

Well, you do, and and it's it's a lot easier, especially if you've got a you know, a 50 gallon a minute pump or something like that to drain it. You can probably drain it in five minutes, you know, maybe 10 minutes, fill it back up in a half an hour and you're done. Yeah, you know, and just start using some dichlore to start to start it, and you'll get some cyanuric acid in it. It's it's a lot easier with a spa to just drain it. The more you can drain it, the better with the spa.

ore Podcasts And Coaching Links

SPEAKER_01 13:59

That's one reason why I leave a sub pump at every hot tub that I do in my service route when am I carrying it back there? And I also tell the homeowner, if you feel like draining it any time, here's how to use the pump. And I show them how to use it with their garden hose, and they can drain it whenever they want to themselves. And as long as they let me know they drained it, I can make sure that I it's had chemicals in it. But one of the things I think is important with a hot tub care is that draining is something that should be part of your service. You shouldn't neglect that aspect of it. And you, of course, you charge for that too. You charge for draining the spa for them.

SPEAKER_02 14:30

I would set it up on uh, you know, 90, 120 days.

SPEAKER_01 14:34

Yeah.

SPEAKER_02 14:35

Just put it on your calendar and do it.

SPEAKER_01 14:37

Yep, exactly. Well, and if you're looking for more podcasts, you can find those by going to my website, SonyPoollearning.com. On the banner, click on the podcast icon. There'll be a drop down menu with 1900 podcast view there. And if you're interested in the coaching program than Africa and learn more at poolguycoaching.com. Thanks for listening to this podcast. Have you got the rest of your week? God bless.