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The best self-cleaning water bottles for tastier tap water

These bottles zap bacteria and viruses to keep you safe and your water tasting fresh.

Typical reusable water bottles are shaped as if manufacturers don't want you to clean them, ever. Most of them don't fit a standard kitchen scrubber, let alone your hand and a sponge. I suppose you could buy a special bottle brush, but hear me out -- what if you never had to clean your reusable water bottle ever again? That could be your reality with a UV-powered self-sanitizing water bottle. 

Unlike filtered water bottles, which use a variety of mechanisms to trap sediment and pathogens, self-cleaning water bottles use UV technology to completely zap waterborne microbes. 

self-cleaning-water-bottles

Left to right: The CrazyCap, Mahaton and Larq bottles all sanitize themselves with UV-C light. 

Amanda Capritto/CNET

Read more: The best water bottles in 2019 that'll make you want to drink more water

The biggest difference between filtered water bottles and self-cleaning water bottles is that the UV technology used in self-cleaning bottles doesn't get rid of dirt and sediment. So while the bottles can kill viruses, bacteria and other micro-organisms that can make you sick, they won't filter out heavy metals or other particulates. 

Because of that, I decided not to test these self-cleaning water bottles outdoors. Instead, I used tap water to find out which self-cleaning bottles stood up to their claims. 

CrazyCap

The CrazyCap bottle has two purification modes: normal mode and "crazy mode." According to CrazyCap, normal mode kills up to 99.99% of contaminants and is suitable for "low to medium contamination," such as from public water fountains and tap faucets. Crazy mode, on the other hand, kills up to 99.9996% of contaminants and is suitable for "medium to high contamination," such as from lakes and rivers. The normal purification cycle takes 60 seconds and the crazy purification cycle takes two and a half minutes. 

The CrazyCap also has an autoclean function, which turns on six times per day for 20 seconds. CrazyCap says this periodical exposure to UV-C light prevents microbial growth and odor, and it seems to work: After three days of use, I didn't notice any smells or films inside the bottle. Additionally, water from the CrazyCap bottle tasted significantly better than water from the tap faucet.

The CrazyCap bottle is more slender than the others on this list, which I liked. It fits into my car cup holders, as well as the mesh cup holders on my gym bag and backpack. It's a bit taller than the Larq and the Mahaton, so you might have trouble fitting it in the top rack of your dishwasher. 

Personally, I think the best thing about CrazyCap is that you can buy just the cap, which according to the website fits on many different water bottles, maybe something you already have. 

On a single charge, the CrazyCap will last up to two months, but only if you leave it to autoclean. Manually starting the purification cycle affects that charge time, though CrazyCap doesn't specify by how much.  

Larq

The Larq bottle also has two purification modes: normal and adventure. Normal mode purifies up to 99.99% of pathogens in 60 seconds, and adventure mode purifies up to 99.9999% of water in three minutes. It doesn't seem like much of a difference, but that 0.0099% can make or break water that comes from a stream or other natural source. 

You can activate purification whenever you want by pressing the top of the bottle, but Larq also comes to life every two hours for a 10-second cleaning cycle. I didn't notice any funky smells or films on the inside of the Larq bottle after three days of constant use.

Larq was the only one of the three bottles that didn't taste significantly better than my tap water, however. It tasted slightly cleaner, but I probably couldn't tell the difference if someone blind taste-tested me. 

The Larq bottle is made of vacuum-insulated stainless steel and keeps your water cold for up to 24 hours. It's sleek and aesthetically appealing -- my only complaint was that there's no groove or curve to fit your hand. You could always purchase the limited-edition bottle sleeve to solve that problem. 

A single charge on the Larq can give you up to two full months of use, assuming you send it through three to four cleaning cycles (in normal mode) per day. If you use adventure mode, the charge will last up to 12 days. 

Amanda Capritto/CNET

The Mahaton self-cleaning water bottle (available for preorder for $44) features one purification cycle that eliminates up to 99.99% of waterborne pathogens. After three days of near-constant use, the bottle didn't show any signs of build-up -- no weird smells, no crusty films. 

Unlike the CrazyCap and the Larq, the Mahaton bottle doesn't have an additional purification setting for bodies of water that might contain more contaminants, such as streams and other sources of groundwater. For that reason, I'd recommend only using the Mahaton bottle with indoor sources of water unless the company releases a new bottle with an additional setting.   

The Mahaton bottle features a sleek shape with a nice double taper that makes it easy to hold. It's made of double-wall stainless steel, so it's durable and it'll keep your water cold for hours. It's also small, so you should have no issues fitting the Mahaton bottle into cup holders or bags. 

One downfall? The Mahaton bottle holds just 12 ounces of water, which I can drink in seconds. Most people would need to refill this bottle up to eight to 10 times each day -- that's a lot of interruptions to your day.

The Mahaton bottle can last up to three weeks on a full charge, assuming you run the purification cycle up to four times per day. That's slightly less than the CrazyCap and the Larq, but not such a short battery life that you'll feel burdened with charging the bottle. 

Which self-cleaning water bottle is best? 

Truthfully, all three of these water bottles did a great job at keeping themselves clean. After three days of constant refills and no hand-washing, none of these bottles smelled musty or had any sort of film on the inside, two things my normal stainless steel bottle often produces.

The Larq, CrazyCap and Mahaton all use UV-C light to zap all of the major waterborne pathogens; they're all made of stainless steel; and they all have automatic cleaning cycles. On top of that, all three are super easy to use and they all have battery notifications so they'll never die without warning. 

I had virtually no complaints about any of these self-cleaning bottles, and if you're looking for an aesthetically pleasing bottle that purifies your water, any of the three will get the job done. 

The only major difference between the three? The Larq and the CrazyCap both have two modes, while the Mahaton only has one. If you plan on using your self-cleaning water bottle with outdoor sources of water, you may want to opt for the Larq or the CrazyCap since they have overdrive modes that kill even more micro-organisms. 

How do self-cleaning water bottles work? 

Self-cleaning water bottles use UV-C light to kill bacteria, viruses, protozoa and other micro-organisms by destroying their DNA. The UV-C light sterilizes both the water in the bottle and the interior surface of the bottle. 

UV-C light serves as a convenient, mostly hands-off way to keep reusable water bottles clean without the need for chemicals or soap. Most self-cleaning water bottles, including the three covered in this article, also have all the features you'd look for in a normal reusable water bottle: They're made of stainless steel, keep liquids hot and cold, and they're durable. 

How did I test these self-cleaning water bottles? 

I tested three UV-powered self-sanitizing water bottles -- the Larq bottle, the CrazyCap bottle and the Mahaton bottle (which is on Kickstarter, but is fully funded and already shipping products) -- using the tap water from my apartment's kitchen sink. 

I usually don't buy bottled water, and I don't have a faucet filter, so I often drink this tap water unaltered. I thoroughly cleaned each bottle and charged them overnight to ensure they were ready for testing. Then, I used each bottle for three days in place of my normal stainless steel reusable bottle. 

What to look for in a self-cleaning water bottle

You should consider five important factors when choosing a UV-powered water bottle like these: Purification, taste, design, ease of use, capacity and battery life. If you decide to purchase a self-cleaning water bottle, you'll want one that kills as many microbes as possible, produces a good taste, is easy to hold and transport, and lasts for a decent period of time on one charge. 

Purification: What does the bottle promise to get rid of, and at what percentage? Also, how long does it take for the bottle to purify the water? Is there an autoclean function? I also considered how the bottle smelled and looked on the inside after three days of use. 

Taste: How does the water taste after going through the purification cycle, compared to my tap water? 

Design: What is the bottle made of and how convenient and easy is it to carry around? Does it keep water cold?

Ease of use: How easy is it to set up the bottle for first use, clean it and store it? 

Capacity: How much water does the bottle hold? Will you be refilling it constantly, or will it last you a while?

Battery life: How long does the bottle last (and how many cleaning cycles can it complete) on a full charge?