How to Raise Alkalinity in a Hot Tub
Everyone, and welcome to Hot Tubs 101 by Swim University, where we help you keep your hot tub clean and clear all year. My name is Matt, and I'm the founder of swimuniversity.com. And on this episode, we're talking about how to raise alkalinity in a hot tub. So let's jump in. Real quick, if you want more help taking care of your hot tub, be sure to grab our free hot tub cheat sheet at swimu.com/ spasheet.
Matt Giovanisci:The easiest way to raise total alkalinity in your hot tub is to use an alkalinity increaser that's specifically designed for hot tubs. But you can also use baking soda to raise alkalinity in a hot tub. And if you go on our website, you can find a chart to determine how much you're gonna need depending on your current reading. So is baking soda the same as alkalinity increaser? Well, yes, it is.
Matt Giovanisci:The the reason is because alkalinity increaser, the main active ingredient is sodium bicarbonate. And in baking soda, that's also the main active ingredient. But you need to make sure that your baking soda doesn't have any additional additives. And we're talking about baking soda, not baking powder. Those are 2 very different things.
Matt Giovanisci:So, you know, you go out, you buy your classic Arm and Hammer baking soda, make sure it has no additives in it, and it's just and look at the active ingredient. It should be sodium bicarbonate. That's what you want. Now, you can use the chart on our website to find out how much alkalinity you need to add to to raise your alkalinity in your hot tub, or you can just use this little trick. It's 1 tablespoon or 17 grams per 100 gallons or 379 liters of water to raise your alkalinity by 10 PPM, which stands for parts per million.
Matt Giovanisci:So let's talk about that's how you raise the alkalinity in your hot tub. But how why do you even need to do it? Like, what is alkalinity? So first, we need to talk about pH. And pH is the balance of how acidic your water is versus how basic your water is.
Matt Giovanisci:And when your water is very acidic, it means your pH is low. And the pH is on a scale from 1 to 14. And then 7, which is right in the middle, that's perfectly balanced. Our human tears, when we cry, those are a pH of 7, which is why it doesn't burn when you cry unless you're wearing makeup or something. If you look at if you had a pH reading of 1, which is crazy acidic, you have to think battery acid, like melting acidic, you know, like just super, super, super, super dangerous.
Matt Giovanisci:On the flip side, if you have a pH upwards of 14 now there's these are measured in just numbers. There's not PPM or pars per million. It's just the number 1 to number 14. If you have pH at 14, think drain cleaner. Again, really, really horrible, dangerous stuff.
Matt Giovanisci:Okay? Now, you're never gonna see numbers that low, and you're never gonna see numbers that high. You're pretty much gonna operate around in a hot tub and in just, you know, hot tub water in general. You'll probably go as low as about 6 maybe, and as high of about 8. Maybe a little bit higher.
Matt Giovanisci:But that's kinda where your range is. So you're really between 6, 7, and 8. Now with pH, the decimal point is very important. Right? For every decimal point, so 7.0 to 7.1 to 7.2 to 7.3, those are all 10 times the amount of acidity or basicness of the water.
Matt Giovanisci:Okay? So the decimal point is crucial, incredibly crucial. So for a hot tub, we like to keep the pH between 7.407.6. So it's a little bit more basic than human tears. In fact, 4 to 6 times more basic than human tears.
Matt Giovanisci:Okay? Now, what about alkalinity? We're talking about pH, but we're we're talking about raising alkalinity. So what alkalinity is, it's a pH buffer. And the way that I like to educate people on what alkalinity is is you have to think of it like, pH's bodyguard.
Matt Giovanisci:Alright? So you wanna keep your alkalinity, your alkalinity reading, which is measured in parts per million, by the way. We like to keep it between a100 and a 150 parts per million. Now, when you have that much alkalinity in the water and your pH is balanced between 7.47.6, when someone gets in the water, if it rains, or anything else that can affect the pH, the alkalinity is going to drop, right, and the pH will remain stable. Okay?
Matt Giovanisci:But they both will come down together, but you have much more room to play in your alkalinity reading. Okay. So we say between a 100a150 parts per million of alkalinity and 7.4 to 7.6. But why are these numbers even important in a hot tub? Well, you don't want your hot tub too acidic because and you don't want your hot tub too basic because when you get in the water and it's acidic, it's gonna feel horrible on your skin and vice versa if it's too high.
Matt Giovanisci:And that's also gonna make your sanitizer, like chlorine or bromine, less effective. Right? So in a hot tub and and not oh, not to mention, if your water is really acidic, it can eat away at the hot tub itself, all of the parts. It can eat away at the shell. And, again, your skin, not fun.
Matt Giovanisci:Okay? But if you're and same with alkalinity, if you're, those those two things go hand in hand. But if your pH is high, you have dryness. Right? Imagine like soaking in a tub of baking soda.
Matt Giovanisci:It would be horribly uncomfortable. You put baking soda on your hands, it's uncomfortable. So by the way, if you're gonna be adding alkalinity to your hot tub, you should be using gloves or and and goggles, ideally. But gloves for sure. Okay?
Matt Giovanisci:Get it on your hands. You know, obviously, people got baking soda in your hands. It's just uncomfortable. It dries out your skin. Okay?
Matt Giovanisci:Now, we say we wanna keep our alkalinity reading between a 100 and a 150 parts per million. You might read somewhere that, wait a minute. I've heard 80 to a 120 parts per million. And maybe in the hot tub space, you've also seen you could keep your, pH as low as 7.2 and as high as 7.8. Sure.
Matt Giovanisci:We just like to keep the the pH at 7.5. To us, that's perfect. Right? It's right in the middle. And we like to keep our alkalinity a little bit higher so the perfect reading for us is a 125 parts per billion.
Matt Giovanisci:Now why it's perfect is that it's a little bit higher, so you're not adding it all the time. Right? It just gives you a little bit more room to play. So we tend to go on the higher side for alkalinity and directly in in like a in a tighter pH range. That's what we like to do at Swim University.
Matt Giovanisci:Alright. So that's it. Now, if you've ever done pH and volatility. Meaning, the pH goes up, it goes down, the alkalinity goes up, goes down. It's hard to balance.
Matt Giovanisci:That's why the alkalinity is so important. Focus on alkalinity before you focus on pH. Because when you add alkalinity increaser or baking soda to raise your alkalinity, you will also be raising your pH. Not as drastically, but it will happen. They go hand in hand.
Matt Giovanisci:Okay? Now how do we test for alkalinity? It's really simple. At Swim University, I like to teach people to use test strips. Again, you're probably gonna hear somewhere else that you should use liquid a liquid test kit because it's way more accurate, and that is true.
Matt Giovanisci:However, we're not trying to be chemists here. We're just trying to get into a hot tub that feels good and that is sanitized. And a test strip is so easy and so cheap. You dip it in, you read the colors on the back of the bottle, and you're done. That's it.
Matt Giovanisci:You don't have to get it doesn't have to be more complicated than that. It certainly can be if you want to. If you want the accuracy, if you're into that sort of thing, go buy a liquid test kit. It's gonna take you much longer and you still have to read colors. So if you're color blind, you're definitely gonna need something digital or someone else to read the colors for you.
Matt Giovanisci:So I think for me, I'm a test strip guy when it comes to taking care of a pool and a hot tub. Now I I brew beer on the side, and I use very, very specific, like, digital testers, because I wanna be as accurate as possible there. We're talking about beverages that we're consuming. And so and we're also talking about a very small body of water. We're only talking about 5 gallons of beer versus 500 gallons of water you're soaking in.
Matt Giovanisci:So for me, it's important to use really advanced equipment to measure those things. But in a hot tub, I don't think you need to do that. Again, feel free to do however whatever you wanna do. So just know that test strips are cheap, they're fast, they're easy to use, but they are less accurate than a liquid test kit, and they're even less accurate than a digital test kit. So you can use basically liquid and a digital test kit, which is what the pros would use when they come out to your house, some of them at least.
Matt Giovanisci:And you can buy one of those if you wanna spend the money. That's totally up to you. And if you have the time and you're into it, go for it. So testing the water is simple. You just add a test strip.
Matt Giovanisci:You take a test strip out of the bottle. Make sure your hands are dry. You don't wanna add any moisture to the bottle. And then you're gonna dip it in the center of the hot tub or as close as possible as you can get. Now why we do it in the center of the hot tub is because we don't want if you have, like, maybe a mineral system or a chemical feeder within the and it's coming out of the jets, we don't wanna take a sample right near where that chemical's coming out.
Matt Giovanisci:Okay? So we just wanna get a nice middle and we and be consistent about where you test so that it's always the same. Right? So you have your test. It's, you know, let's you you you wanna shake off you wanna test the dip the test strip.
Matt Giovanisci:Okay? You wanna dip the test strip in the water, shake off any excess water, and then wait about 15 seconds, and then match up the colors on the back of the test strip or on the test strip to the back of the bottle. Right? That's your readings. And it you're gonna be close.
Matt Giovanisci:Right? Because it's like, oh, it's kinda green. Oh, this is kinda red. You know, if you're in the range, great. Leave it alone.
Matt Giovanisci:If you're low, you'll know. Okay? Now here's a step by step guide on how to raise alkalinity and pH in a hot tub. So it doesn't matter if you've just filled the hot tub with fresh water or you've been soaking in it for a a long time. This exact these steps, there are 5 steps, they will all apply.
Matt Giovanisci:Okay? So number 1 is you're gonna first test the water to determine the current pH and alkalinity levels. Easy. Number 2, you're gonna turn on the hot tub jets on low, and you're gonna go around your hot tub and turn off all of the air valves. Right?
Matt Giovanisci:Those are those big dials that you see on top of some hot tubs. And what that does is it turns off your air blower. If you turn it on, you'll notice your jets. There's a lot more bubbles. Your water will be a lot more cloudy because it's injecting air into the jets, which is great when you're sitting in it because you get more pressure on your back, but it's not good for adding chemicals and especially pH.
Matt Giovanisci:In fact, adding, air to your system will actually lower your pH. K? So turn off the air valves, keep your hot tub gents on low. You just want the water circulating enough. Number 3 is you're gonna add the correct amount of alkalinity increaser or baking soda depending on your current reading.
Matt Giovanisci:And Again, you can go to our website swimuniversity.com to find our chart, or you can just do that one tablespoon for every 100 gallon to raise it 10 parts per million. Okay? Now, you wanna wait once you add the the chemical. You just wanna sprinkle it in, you know, as close to the water as possible so it doesn't get blown up in the air. Okay?
Matt Giovanisci:This is why you wear goggles when you when you're adding chemicals, dealing with chemicals. You wanna wait 5 to 15 minutes to let the chemical mix into the water. I've noticed it really especially baking soda or alkalinity increaser or even pH increaser, it mixes in really fast, especially if you have the jets going. So you really just have to wait 5 minutes. And then, by the way, you also wanna leave the cover off during this time.
Matt Giovanisci:You don't wanna put your cover back on. And then you wanna retest the water to make sure that you hit the ideal range. If you didn't, repeat the steps. If you got it, you nailed it. And that's it.
Matt Giovanisci:And then if your pH, you know, is slightly off, you know, maybe it's still a little bit low, then you can add just pH increaser to tweak that number up. Adding the pH increaser will increase alkalinity a little bit but it's gonna it's gonna target pH a little bit more. Okay? And again, if you're if you add alkalinity and your pH is too high, you can add pH decreaser. So things that I would have always on hand at all times in the proper size bottles built for hot tubs is alkalinity increaser or baking soda, pH increaser, and pH decreaser.
Matt Giovanisci:Okay? So you gotta if you're if you're a guitar player or you've ever, tuned an instrument, you wanna think about, the alkalinity being the big tuner. Right? Getting it to, like, the general, area. And then the pH decrease or increase, or you're just fine tuning that pH number.
Matt Giovanisci:K? Alright. Finally, here are some quick tips on how to keep alkalinity balanced in your hot tub. And then we'll go go over some frequently asked questions and then we'll wrap up the episode. Okay.
Matt Giovanisci:So couple of tips. 1, you wanna regularly test every single week or after every single use. You wanna make sure that you're running that hot tub and you're circulating it through the filter system. That's gonna help keep the alkalinity and pH balanced. You wanna clean your filters regularly.
Matt Giovanisci:That means every week, take them out of the hot tub, rinse them down with cold water or hose water, whatever you wanna do. Every month, you're gonna spray them down with a nice, cleaner. And every 3 to 4 months when you're draining and cleaning your hot tub, you're gonna wanna soak those filters. You know, the more you use your hot tub, the more it's gonna deplete chemicals and the more you're gonna have your pH and alkalinity out of balance. Just know that, which is why if you use it a lot, test it a lot.
Matt Giovanisci:That's all. You know, you wanna change your hot tub every 3 to 4 change your hot tub water, sorry, not your whole hot tub, your hot tub water every 3 to 4 months. Because over time, as you keep adding chemicals and chemicals and chemicals to your water, it starts to just get saturated. That's called total dissolved solids. It's a reading that you don't really need to worry about because you really should be draining your hot tub every 3 to 4 months.
Matt Giovanisci:But, you know, it gets oversaturated with all these chemicals, and then they become less effective overall, so you just wanna drain and refill. And finally, I would just follow a maintenance schedule. And you can go on our website, swimuniversity.com/spasheetorswimu.com/spasheet and download our cheat sheet, which will help you create a maintenance schedule for your hot tub. Now, finally, let's talk about some frequently asked questions about raising alkalinity in a hot tub. And let's see if I have any here.
Matt Giovanisci:Can you raise alkalinity in a hot tub without raising pH? No. When you when you add alkalinity, you will raise the pH slightly. That's gonna happen. Can you use the hot tub if your alkalinity is too high?
Matt Giovanisci:I would say don't. It's gonna feel like it's gonna feel horrible on your skin. Your skin's gonna feel incredibly dry, itchy, it and you're gonna get eye irritation if you or if you're near it. I would make sure that your pH and alkalinity are balanced before you get in it. Should you adjust the pH or alkalinity first?
Matt Giovanisci:Which one do you adjust first in the hot tub? Always adjust alkalinity first. If you're if you test the water and your alkalinity is good but your pH is low, then obviously, you're just gonna, you know, use pH increaser. But if your pH and alkalinity are both low, if you add alkalinity, you may not have to add pH because the alkalinity increaser will take care of it. Will shocking a hot tub lower alkalinity?
Matt Giovanisci:No. Shocking will actually raise the alkalinity in a hot tub. It's yeah. Shock has a, a high pH. And that's if you use a chlorine shock.
Matt Giovanisci:Now, if you're using a non chlorine shock, that's gonna have less impact, which is why we at Swim University recommend that you shock with a non chlorine shock, as a weekly, as a weekly regular maintenance. If you're having a problem with algae or cloudy water, then, yes, you're gonna wanna use a chlorine shock. And then finally, I I had mentioned this earlier about how long does it take for baking soda or p or alkalinity increaser, sodium bicarbonate, to raise the alkalinity in a hot tub. And for me, whenever I add alkalinity, I get a reading almost immediately. I see a difference immediately, but I would at least wait 5 minutes.
Matt Giovanisci:That's a good rule of thumb. You can wait up to 15 minutes. Some people I've seen, say wait an hour or even the next day. Obviously, the longer you wait, the more it's gonna mix in, the better it's gonna be. But if you don't have time for that, I think 5 minutes is fine.
Matt Giovanisci:That's a good that's a good waiting period. Right? You know, add it, go do something, come back, test it, and you're good to go. Okay. Well, that's it for this episode.
Matt Giovanisci:And remember, if you need more help with hot tub maintenance, grab our free hot tub cheat sheet at swimu.com/spasheet. And If you found this episode helpful, subscribe for more hot tub maintenance tips on your favorite podcasting app. And when you do that, please leave us a review. Your support will help us find more hot tub owners like you, and then get access to this show. So that's it.
Matt Giovanisci:Thanks again, and happy soaking.
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