When it comes to flavored water bottles, the market isn’t exactly crowded with equals. There are two giants towering above the rest, Air Up and Cirkul, and then there’s everyone else scrambling in the shadows.
Their popularity and viral status eventually caught up with me, so in mid-2024 I bought both bottles and started putting them to the test. Since then, I’ve easily downed hundreds of liters through each system, which gives me a solid foundation to declare a favorite.
And I won’t keep you waiting until the last paragraph for the reveal: Cirkul is the clear winner for me. The decision wasn’t even all that difficult. Still, I wouldn’t dismiss Air Up just yet. The concept is fresh, the design is fun, and with the right improvements, it could absolutely challenge Cirkul’s dominance in the future.
Read on, and I’ll walk you through exactly what worked, what didn’t, and how these two bottles stack up head-to-head.
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Air Up vs Cirkul: Comparison Table
Cirkul | Air Up | |
|---|---|---|
 |  | |
Flavor delivery system | Cartridges | Pods |
Cost per 32 oz. of flavored water | $1 | $0.40 – $0.60 |
Materials | Tritan plastic, 18/8 stainless steel | Tritan plastic, 18/8 stainless steel |
Leakproof? | YES | YES |
Can be used with hot liquids? | NO | NO |
Bottle warranty | 12 months | 24 months |
Sweeteners | Sucralose, stevia, unsweetened | None |
My Score | 4.5/5 | 3.9/5 |
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Technology & Concept
The first and most obvious difference between Cirkul and Air Up lies in how they bring flavor to your water.
Cirkul keeps it straightforward: cartridges pre-filled with actual flavor fluid. Tilt the bottle, sip, and the water flows through the cartridge, mixing with the flavor. The greatest feature, though, is the 10-level flavor dial on the lid. Ten levels!
I honestly can’t put into words how satisfying it is to adjust the flavor depending on my mood – sometimes I want a subtle hint, other times I want full-on sweetness. You even have the option to block the cartridge entirely and drink plain water if you feel like it.
Air Up, on the other hand, flips the entire concept on its head. It doesn’t add flavor to your water at all. Instead, it tricks your brain into tasting flavor using retronasal smell – the fancy way of saying “your nose helps your brain experience taste”.
Here’s how it works:
Each pod contains natural aroma – peach, berry, cola, you name it. You attach the pod to the straw or spout of your Air Up bottle. When you sip, the water itself remains pure and flavorless.
Simultaneously, air passes through the aroma pod, carrying scent molecules up the back of your nasal cavity. Your brain interprets these smells as flavor. In other words, you’re drinking plain water… but your brain insists it’s a juicy peach or fizzy cola.
Flavor Experience
At first glance, Air Up’s technology seems irresistible. You drink plain water while tricking your brain into tasting flavor. I was hooked too. I even bought roughly half of the 25+ Air Up flavors available.
But when I actually used it… I was underwhelmed.
The flavor intensity is simply too subtle. I don’t need my water to taste like maple syrup, I just want it to mask the plain water taste a little. Even with those modest expectations, the Air Up pods fell short. Sometimes I sip and… nothing.
So subtle, in fact, that I can barely tell which flavor I’m drinking. It works occasionally for a gentle hint, but if you need a clear, noticeable flavor, Air Up may leave you disappointed.
With Cirkul the story changes entirely. With over 100 flavors, plus limited editions dropping every month, it immediately outshines Air Up in variety. I’ve tried nearly 50 flavors myself, and honestly, almost all of them hit the mark.
Everyone’s taste buds differ, of course, but only a handful of flavors didn’t impress me. My personal favorite? Gateway Tea – a perfect starting point if you feel overwhelmed by Cirkul’s massive catalog.
Variety is just the beginning. What truly sets Cirkul apart is the 10-level flavor dial on the lid. Being able to adjust the intensity throughout the day is practical, fun, and addictive. I often switch levels 5–6 times a day depending on my mood.
In terms of flavor experience, Cirkul is miles ahead of Air Up. The combination of bold, tasty flavors and precise control makes it my clear favorite.
Bottle Design & Options
Let’s talk about the vessels themselves. Both Cirkul and Air Up offer a surprisingly wide variety of bottles, catering to different preferences and lifestyles.
Cirkul’s lineup includes:
- Stainless steel insulated bottles
- Plastic bottles (BPA-free)
- Squeeze plastic bottles (BPA-free)
- Stainless steel insulated tumblers
Air Up offers:
- Stainless steel tumblers
- Plastic Air Up Click
- Plastic Air Up Twist
- Twist Pro (plastic/stainless steel)
- Pod-ready straw
Right now, I own the Cirkul 22 oz. squeeze bottle and the 21 oz. Air Up Click, both plastic but I’m planning to upgrade to stainless steel versions for insulation.
I love my Cirkul squeeze bottle because I’m active and squeezing water straight into my mouth while running or playing soccer is incredibly convenient. Its lids feature a thin membrane that makes the bottle practically leakproof even if the cap isn’t fully closed. You can turn it upside down, and water won’t flow, it only comes out when you squeeze.
The bottle’s sides are ergonomically designed with sunken, anti-slip material, making it comfortable to hold and nearly impossible to drop.
Air Up bottles stand out for their quirky, eye-catching designs. They feel fun and modern. My main gripe is the lid – when a pod is attached, you need to press quite hard to hear the satisfying “click” that locks it in. Not a big deal for adults, but it could be tricky for kids.
Both brands offer a wide range of colors and sizes. Cirkul has an impressive lineup: 12, 22, 26, 32, 40, 42, and 64 oz, giving you plenty of options.
In the end, both Cirkul and Air Up deliver high-quality, functional bottles, but I’d give a slight edge to Cirkul for practicality, especially for active users.
Ease of Use & Cleaning
You might imagine that using these bottles requires a PhD in hydration and a 30-page instruction manual. Well, setting up both Cirkul and Air Up took me all of… 30 seconds.
Cirkul: Grab a cartridge with the lid (already attached), pour water into the bottle, screw it on, choose your flavor intensity, and done.
Air Up: Even faster. Pop your scent pod on the spout, pour water in, and you’re ready to drink.
When it comes to cleaning, both bottles are dishwasher safe (top rack only), but I usually wash them by hand in 1–2 minutes. Cirkul even edges out slightly on convenience because the lids are disposable once the cartridge is empty. I drink about 60 oz of water daily, so after two days, I just swap the cartridge – no lid scrubbing required.
And here’s the underrated win both bottles share: you’re only ever pouring water in. Cirkul mixes flavor in the cartridge, and Air Up relies on scent pods, so the bottles themselves stay virtually clean. No leftover sugary residue, no funky smells, no mold waiting in the corners. I typically clean mine once every 2–3 days, and it’s totally fine.
Cartridge/Pod Longevity
Naturally, we want our cartridges and pods to last as long as possible. On paper, Air Up clearly excels in this area. According to the brand (and my own testing), each pod flavors about 5 liters (≈170 fl oz) of water. That’s quite a lot of hydration before you need a refill.
Cirkul, on the other hand, claims that a single cartridge lasts for 120 fl oz of water. But here’s the twist: in Cirkul, you control the flavor intensity. If you’re like me and stick mostly to level 3 out of 10, a cartridge can stretch close to that maximum. Crank it up to levels 7-10, though, and suddenly it’s gone in half the time.
Important to note: the flavor doesn’t suddenly disappear. Instead, the cartridge gradually releases less and less. For me, the first three 22 oz bottles taste fine at level 3, but starting with the fourth bottle I usually need to bump it up to level 4, and eventually to level 5, 6, or higher to keep noticing the flavor.
So yes, Air Up wins in sheer longevity. But for me, flavor control matters more than lifespan. I’d rather swap Cirkul cartridges more often than settle for Air Up’s subtle taste.
Health Aspect
Okay, both bottles have interesting features, but which one can we actually call “healthy”? For me, the answer is… both.
Air Up is the obvious case. You’re drinking plain water. That’s it. The only thing standing between you and a glass of tap water is the bottle itself, which is made of BPA-free Tritan plastic – so even that’s not a concern.
Cirkul is a little more complicated. Most flavors use sweeteners like sucralose or stevia, and yes, sucralose can make some people raise an eyebrow. I was the same before I bought my first Cirkul.
Sucralose is 600 times sweeter than sugar, but it’s non-caloric because your body doesn’t use it for energy. Regulatory agencies like the FDA, EFSA, and WHO all consider it safe for human consumption.
In fact, Cirkul has helped me cut sugar without feeling deprived. And if you’re strictly anti-sweetener, they even offer unsweetened flavors. If you’re interested in the health side of Cirkul, check out my guide Is Cirkul Healthy? where I break it down in detail.
Verdict: Cirkul Wins For Me
It’s easy to see why Air Up appeals to people who would rather not hear the words “artificial sweetener”. For those seeking the most natural way to add flavor to their water, Air Up has serious potential. That said, the technology isn’t quite there for me yet. The flavors are just too subtle and I often find myself reaching for my Cirkul instead.
Of course, taste is personal. I recently handed an Air Up to my parents, and they loved it. In fact, they preferred it over Cirkul. If you’re the type who wants just a whisper of flavor while hydrating, Air Up can be a solid choice.
So, I’m not writing off Air Up entirely. If they ever crank up the intensity of their pods, I’ll be the first in line to try it. For now, though, if you want a reliable, flavorful, and customizable experience, Cirkul is still my top recommendation.
Cirkul | Air Up |
|---|---|
| |
Jeremiah Kowalski
Hey there! I’m Jeremiah, the guy behind WaterBottleAdvisor.com. I used to have a bad habit of guzzling sodas while working remotely, but thanks to reusable water bottles, I’ve turned my hydration game around. After testing over 50 bottles, I’m here to help you find the perfect one to make staying hydrated a joy, not a chore. When I’m not reviewing bottles, you’ll likely find me scaling steep trails around the world, trusty water bottle in hand.
