We’ve put 5 bath filters to the test under real world conditions to see which perform best, and which aren’t worth the money.
Most bath tub water filters promise softer skin, healthier hair, or cleaner water, but the average consumer is unlikely to see or feel a noticeable difference after using one. Misleading or inaccurate performance claims are also common, which can make it even more difficult to know what you can realistically expect from a product.
That’s why we’ve gone beyond surface impressions and gathered real data for these filters in our testing, for contaminant reduction, water hardness, flow rate, and more.
Santevia
Canopy
Sprite Bath Pure
The Santevia Bath Filter received the highest overall weighted score of all the products we tested. It was the only bath water filter that reduced chlorine down to 0 PPM at a more “normal” fast faucet flow (more on our flow testing later). It also received one of the highest design scores due to its minimal use of plastic compared to other models, and setup and maintenance were equally as easy as all the filters we tested.
Table of Contents
Testing & Selection Process
When we’re testing water filters for our guides, we put every product through a customized performance analysis, focusing particularly on our objective and data-driven testing.
Contaminant reduction is our top priority, but we also consider factors including filter design, setup and maintenance requirements, and the manufacturer’s warranty and shipping policies.
For our Best Bath Water Filters list, we ranked a selection of the most popular filters in this product category, based on our testing and formulaic scoring. We tested each filter against six key performance factors: contaminant reduction, filtration rate, design, setup, maintenance, and company policies. We also compared upfront costs, which aren’t a ranking factor but help us determine overall value for money.
We use objective and measurable data wherever possible in our testing, supported by our own subjective assessment for performance categories that are difficult to assess quantifiably. You can see our complete testing and scoring process here.
Our Contaminant Reduction Testing
In the contaminant reduction category, we were specifically interested in evaluating a filter’s ability to reduce contaminants that may affect bathwater quality, rather than drinking safety. We tested all filters with city water in Colorado, gauging their ability to remove:
Chlorine, which has several possible skin effects in bathing water and may exacerbate conditions like atopic dermatitis.
Disinfection byproducts, which have been widely studied and associated with increased rates of bladder and colorectal cancers, heart issues, and miscarriages, due to inhalation and dermal (skin) exposure.
Hardness, which damages the skin barrier and has been linked to eczema in numerous studies.
Our contaminant reduction testing process is tailored to the product category we’re assessing. For bath tub filters, we lab-tested one sample of filtered cold* water for each filter.
We then compared these results against an unfiltered baseline sample of water directly from our bath faucet.
Our testing process was a little different for chlorine reduction and involved using on-site test strips. Why didn’t we lab-test it with the other contaminants? Due to chlorine’s volatility, it can’t be accurately detected at a lab due to dissipation while collecting and shipping the sample.
We originally conducted just one chlorine test at a normal fast flow, taken after filtering water at the maximum faucet flow without overflow (water leaking out of the top of the filter). But with this faster flow, we saw poor chlorine reduction across the board.
We know that most water filters offer better contaminant reduction when the filtration process is slower (due to increased contact time with the media), leading us to conduct a second chlorine test at a slower flow to see if there would be better chlorine reduction.
Note that we couldn’t adjust the faucet flow after swapping products to be identical every time, so our measurements aren’t 100% precise. Our aim instead was to test the theory that slower flow = better chlorine reduction.
*Why did we use cold water in our filters?
We know that most folks use hot bath water, but we wanted to get the best indication of performance for chlorine, as well as other VOCs that are highly volatile and dissipate into the air quickly, particularly from hot water. Testing with cold water helped us gauge a filter’s ability to remove these contaminants, with a lower likelihood of reductions due to dissipation.
We looked at the totality of our tests and individual scores when selecting and ranking the best bath filters for this guide. We analyzed this data side-by-side to compare each filter’s overall performance and value for money.
We ranked the filters from best to worst based on their overall weighted score. To be included in this list, all filters needed to be:
Available in the US, with replacement filter cartridges easy to find
Sold by legitimate manufacturers with traceable company data
Best Bathtub Filter Summery
| Product | Santevia | Canopy | Sprite |  Crystal Quest |  Tubo |
|---|---|---|---|---|---|
| Score | 8.17 | 8.08 | 8.00 | 7.94 | 7.91 |
| Price | $19.99 | $89.00 | $29.99 | $64.95 | $64.99 |
| Certifications | Not Certified | Not Certified | Not Certified | Not Certified | Not Certified |
| Filter Capacity (gal.) | 3000 | 2700 | 900 | 2,500 | 2,500 |
| Cost per Gallon | $0.008 | $0.014 | $0.022 | $0.016 | $0.014 |
| Warranty | 30 days | 1 year | 1 year | 1 year | 60 days |
The aim of our testing was to assess the performance of the most popular bath water filters sold today. We reviewed bath filters sold by established, reputable brands like Canopy and Sprite, as well as products that are newer to the market, like Tubo.
Video Review
Baseline Water Sample
Our baseline water sample was taken directly from our bath faucet before installing or using any of the bath filters. A range of contaminants were detected in the water, but we were specifically interested in those with known health effects in bath water: chlorine (a common tap water disinfectant), hardness, and disinfection byproducts.
Initially, our water contained 2 PPM of chlorine. This is within the “safe” range (up to 4 PPM) established by the EPA.
The rest of our contaminant analysis was conducted through Tap Score testing. We shipped samples of our baseline water (as well as all filtered water samples) to be tested in the lab, and received our results via interactive test reports.
Our total water hardness reading was 17.13 PPM, which just edges it into the “slightly hard” category. For reference, soft water is defined by NSF/ANSI 44 and NSF/ANSI 330 as water containing <17.1 PPM of hardness.
24.7 PPB of chloroform (a disinfection byproduct) was also detected, exceeding the protective Health Guideline Level of 0.221 PPB by 11,075%. Chloroform and other DBPs are generated as a result of a reaction between chlorine and naturally occurring organic matter in the water.
Several other contaminants (which are better-known for their health effects when ingested, rather than due to dermal exposure or inhalation) were also detected, including 0.05 PPM aluminum, 0.0066 PPM barium, 0.0015 PPM copper, 0.5 PPM fluoride, 1.2 PPM phosphorus, and 0.017 PPM strontium.
See Also: The Best Shower Filters We’ve Tested
Santevia Bath Filter
The Santevia Bath Filter is the top-performing bathtub filter in this list. It received the highest overall score, and this was largely down to its contaminant reduction performance (it was the highest-scoring filter in this category). It stood out in our testing as the only bath filter that could reduce 100% chlorine even with a “normal”, faster faucet flow rate.
What We Like
Product Specs
| Price | $19.99 |
| Contaminants Removed | Chlorine |
| Certifications | Not Certified |
| Process | Calcium Sulfite + Activated Carbon |
| Filtration Capacity | 2 months |
| Annual Cost | ~$120 |
| Warranty | 30 days |
Specs
Santevia’s take on a bath filter is unique: rather than having an all-plastic outer shell, this product is an organic cotton bag that hangs underneath a bath faucet. It wins brownie points for its use of a non-plastic housing, although the loofah inside is still made from plastic.
The filter costs $20 (at the time of writing this review), making it the most affordable upfront on this list. Santevia claims that it can both reduce chlorine and infuse bath water with minerals like zinc and magnesium, helping to support skin barrier health and protect against dryness and irritation.
Chlorine
In our chlorine reduction testing, here’s how the filter performed.
1. In our “fast flow” test (with an average flow rate of 1.65 GPM), the filter eliminated chlorine down to 0 PPM: a 100% reduction.
2. In our “slow flow” test (with an average flow rate of 0.36 GPM), the filter performed exactly the same, reducing 100% chlorine.
This Santevia filter was the only filter in our testing to completely eliminate chlorine in the fast flow test, which is a massive bonus. With all the other filters, we had the issue of the increase in fill times—it’s not practical to take an extra 30-60+ minutes to fill a bath just to achieve 100% chlorine reduction. This was not an issue with the Santevia Bath Filter, which eliminated chlorine with a bath fill time of just over 18 minutes.
The manufacturer has tested the filter to NSF standards 42 & 53 for chlorine reduction and “water quality” (yes, that vague), demonstrating a >99.9% reduction in chlorine, consistent with our own results.
Hardness
Our data did present a trade-off for this superior chlorine reduction result: hardness increase.
Post-filtration, our total water hardness was 74.81 PPM (a 336% increase from the baseline sample), and the TDS of our water was 98 PPM (a 151% increase).
The filter also increased sulfate by 257% (from 5.9 to 21.2 PPM), magnesium by a massive 2,626% (from 0.53 to 14.4 PPM), bicarbonate by 169% (from 17.04 to 45.94 PPM), and carbonate by 1,316% (from 0.012 to 0.17 PPM). The pH of our water increased from 7.2 (close to neutral) to 7.9 (slightly alkaline).
Is this an expected outcome? Yes—we know that the Santevia Bath Filter contains an undisclosed “mineral blend” media that adds magnesium and zinc deliberately for their claimed “skin nourishing” benefits.
The carbonate and sulfate increases suggest that the filter contains magnesium carbonate and magnesium sulfate compounds. Since magnesium is a hardness mineral and contributes to alkalinity, it makes sense that the total hardness and pH of our water increased. That said, it’s not good news if you’re concerned about the skin and hair effects of hard water in your bath water.
DBPs
As for chloroform, this disinfection byproduct was only reduced by 2.83% in our filtered water. This suggests an incidental reduction only and tells us that the filter isn’t designed for removing DBPs.
Other Detections
While our main focuses were chlorine, disinfection byproducts, and hardness, we conducted broader lab testing to help us evaluate each filter’s contaminant reduction performance on the whole.
Our testing showed that Santevia removed 100% aluminum. Fluoride and phosphorus concentrations remained the same, while copper increased by 5%, barium by 6%, and manganese by less than 1%. While these smaller increases were likely incidental, they tell us that the filter doesn’t effectively address these contaminants.
Subjective Feedback
For all the bath filters we tested, we measured the filtration rate using the “slow” flow that provided more thorough chlorine reduction. Even though the Santevia Bath Filter reduced 100% chlorine at the faster flow, we still measured its slower filtration rate for consistency across our data.
We calculated flow rate by timing how long the filter took to fill 2 cups of water. We repeated this three times, took an average, then converted this to GPM (gallons per minute). Santevia measured at just 0.36 GPM—the slowest of all the bath tub filters we tested, resulting in a score of 8.50. At this flow rate, it would take just over 84 minutes to fill an average 30-gallon bath.
Where the filter stood out for the right reasons was design. Most bath filters use plastic housing containing a cartridge, but the Santevia Bath Filter uses a cotton bag, minimizing the potential for microplastics or BPA/BPS leaching. That said, it still contains a loofah made from BPA- and BPS-free polyethylene, so it’s not completely plastic-free. Plus, its score was pulled down to 7.20 due to its lack of materials safety certifications.
As with all the filters we tested, Santevia’s product was easy to hook onto the end of our faucet, with no tools or DIY required. Maintenance is also easy and affordable (the filter lasts two months on average), resulting in high scores of 9.50 and 9.75, respectively.
Santevia offers a 30-day warranty and returns policy, but its free shipping only applies to orders over $99 and excludes certain regions, resulting in a slightly lower company score of 7.75.
| Criteria | Results |
|---|---|
| Health Related Contaminants | 7.90 |
| Aesthetic Related Contaminants | 9.90 |
| Performance Certification | Not Certified |
| Filtration Rate | 0.36 -1.65 GPM |
| Component Quality | Fair |
| Component Certification | Unsatisfactory |
| Setup | Outstanding |
| Servicing Requirements | Outstanding |
| Costs | $0.008/ gallon |
| Warranty Length | 30 days |
| Shipping | Free shipping on orders over $99, excluding Hawaii, Puerto Rico, Alaska and rural areas |
| Returns | 30 days |
Canopy Bath Filter
The Canopy Bath Filter took the second spot on this list, with the second-highest overall score. It has a more premium look and feel than the cheaper plastic bath ball filters that you might be familiar with, with a unique design that fits over the entire faucet. But while its exterior might look higher-tech, our contaminant reduction results were meh, suggesting it isn’t any fancier on the inside than its cheaper competitors.
What We Like
Product Specs
| Price | $89 |
| Contaminants Reduced | Chlorine |
| Certifications | Not Certified |
| Process | Calcium Sulfite + Activated Carbon + KDF |
| Filter Capacity | 2,700 gallons |
| Annual Cost | ~$74 |
| Warranty | 1 year |
Specs
Canopy’s bath filter is designed with a built-in spout cover and comes with several attachment bands to match your spout size. There’s potentially more of a compatibility risk with this filter, since it needs to fit over the entire faucet to sit comfortably. The outer shell is silicone, rather than plastic, which did slightly boost its design score.
The filter costs $89, making it four times more expensive than Santevia’s filter. Canopy claims that it can reduce chlorine and “harsh contaminants”, so every bath is “cleaner, gentler, and better for your skin”.
Our Lab Tests
The Canopy Bath Filter received a score of 7.54 for contaminant reduction: the second-highest score (joint with Sprite) following Santevia.
Chlorine
When it came to reducing chlorine, our results for the Canopy Bath Filter were less impressive than Santevia’s:
- In our “fast flow” test (with an average flow rate of 3.60 GPM), the filter reduced chlorine down to 1 PPM: a 50% reduction.
- In our “slow flow” test (with an average flow rate of 0.60 GPM), the filter reduced 100% chlorine.
This tells us that Canopy’s bath filter requires a longer contact time for chlorine reduction to be 100% effective. At this slower faucet flow, it would take almost 50 minutes to fill an average 30-gallon bathtub with water, which isn’t ideal. Our data suggests that the only way to achieve 100% chlorine reduction is by filling your bath very slowly, which is both inefficient and will make it harder to maintain your desired water temperature by the time the bath is full.
The Canopy Bath Filter has supposedly been tested to NSF/ANSI 177, a certification standard that’s awarded to shower filters for free chlorine removal. The filter doesn’t have any official performance certifications, and we couldn’t find any third-party test results online.
Hardness
The hardness, TDS, and alkalinity of our water were impacted only slightly after installing the Canopy Bath Filter, telling us that the filter media doesn’t introduce minerals or impurities that significantly influence these properties.
Total hardness increased by just 5%, while TDS was reduced by just over 2%, and pH stayed the same. Magnesium increased by around 15%, sulfate by 10%, and carbonate by 16%. That’s good news if you’re concerned about the effects of hard water and don’t want your bath filter to increase hardness.
Interestingly, calcium only increased by 5%, despite the fact that the filter contains calcium sulfite media (which releases calcium ions as it reacts with and neutralizes chlorine) along with activated carbon and KDF-55.
DBPs
Our filtered water actually contained 6% more chloroform than our unfiltered baseline sample. This was likely an incidental difference between sample collection and simply tells us that the filter is unable to address disinfection byproducts.
Other Detections
Canopy effectively removed 100% aluminum in our testing, but, aside from chlorine, this was the only reduction recorded. The other contaminants detected in our water either increased or remained the same: barium increased by 12%, copper by 5%, fluoride by 20%, manganese by less than 1%, strontium by 5%, and phosphorus not at all.
While the copper increase could be due to the KDF-55 media, we hypothesize that the other increases are simply due to incidental fluctuations in contaminant concentrations between the unfiltered and filtered water tests.
Our Hands-On Testing
The Canopy filter had an average flow rate of 0.60 GPM in our low-flow testing, resulting in a score of 8.50. While its filtration rate can be faster, we’ve used the slower faucet flow when scoring the filter because it was at this rate that chlorine was reduced by 100%.
Canopy’s design score of 7.20 matched Santevia’s. We rated the filter’s component quality as better than most others because its outer shell is silicone, rather than plastic. However, its lack of a materials safety certification prevented it from getting a higher score in this category.
The filter has the same easy setup and maintenance requirements as other models, earning scores of 9.50 and 9.75. The install process takes less than 5 minutes, and the filter can be removed and replaced by pulling it out of the bottom, without having to remove the entire unit. The housing is dishwasher-safe, so it’s easy to deep-clean.
Canopy’s company policies are better overall than its competitors, with its 1-year warranty, free US shipping for orders over $25, and 60-day guarantee achieving a combined score of 8.80.
| Criteria | Results |
|---|---|
| Overall Score | 8.08 |
| Health Related Contaminants | 7.70 |
| Aesthetic Related Contaminants | 8.00 |
| Performance Certification | Not Certified |
| Filtration Rate | 0.60 GPM |
| Component Quality | Fair |
| Component Certification | Unsatisfactory |
| Setup | Outstanding |
| Servicing Requirements | Outstanding |
| Costs | $0.014/ gallon |
| Warranty Length | 1 year |
| Shipping | Free to US on orders over $25 |
| Returns | 60 days |
Sprite Bath Pure Filter
The Sprite Bath Pure was a close third runner-up behind Canopy. It’s more basic in design, but Sprite is a well-known manufacturer with a mostly positive reputation, particularly in the bath and shower filter space. It didn’t blow us away with its performance, but we think it’s a solid choice for folks looking for no-frills chlorine reduction.
What We Like
Product Specs
| Price | $29.95+ |
| Contaminants Removed | Chlorine |
| Certifications | Not Certified |
| Process | Calcium Sulfite + KDF |
| Filtration Capacity | 900 gallons |
| Annual Cost | ~$240 |
| Warranty | 1 year |
Specs
The design of the Sprite Bath Pure filter is simple, with a strap that wraps around the bath faucet which holds a hook for the filter underneath the spout. It’s made from ABS food-grade plastic and is available in three housing colors: chrome, white, and transparent blue.
Prices range from around $30 to $32.50, depending on the finish, putting it in the “affordable” category along with Santevia. The filter contains Chlorgon (Sprite’s proprietary media made from a blend of copper, zinc, and calcium sulfite), the same as the Sprite Shower systems, which Sprite claims can remove “chlorine, sediment, bad odors and other harmful contaminants”.
Our Lab Tests
The Sprite Bath Pure filter matched Canopy in our contaminant reduction testing, receiving an equal score of 7.54 in this category.
Chlorine
Here’s how Sprite performed in our two chlorine reduction flow tests:
- In our “fast flow” test (with an average flow rate of 2.53 GPM), the filter reduced chlorine by 50%, down to 1 PPM.
- In our “slow flow” test (with an average flow rate of 1.01 GPM), the filter eliminated chlorine to undetectable levels.
So, like Canopy, Sprite can only effectively eliminate chlorine when the water has an impractically long contact time with the filter media. In Sprite’s case, we calculated that it’d take just under 30 minutes to fill an average 30-gallon bathtub with the “slow flow” faucet speed— around 20 minutes faster than Canopy, but still not great.
The Sprite Bath Pure Filter has also been tested to NSF/ANSI 177 (for shower filters that remove free chlorine), but it’s not officially certified. However, it’s the closest to being certified of all the bath filters we tested, because it uses the same patented Chlorgon & KDF filter as Sprite’s Shower Filters, which are NSF/ANSI 177 certified.
Hardness
We saw only incidental increases in total hardness (by around 3%), and calcium (by 5%) after installing the Sprite filter, and magnesium concentrations remained the same, telling us that it doesn’t increase or decrease hard water minerals. The Chlorgon media is said to contain copper, zinc, and calcium sulfite, but our results show that calcium leaching doesn’t occur (at least not while the filter is relatively new).
The pH of our water increased only slightly, from 7.2 to 7.3,, and TDS was reduced by just 2% (again, likely an incidental result).
DBPs
We saw only a slight decrease in chloroform (less than 1%) with our Sprite-filtered water. This tells us that the product is unable to remove disinfection byproducts at all.
While we haven’t tested the filter’s long-term performance, it’s worth highlighting a possible benefit of its lack of carbon media. Hot water can inhibit the removal of certain organics and may also damage activated carbon, affecting a filter’s performance throughout its lifespan. Sprite’s no-carbon design is, therefore, better suited to its purpose of filtering hot water and may have long-term performance benefits compared to carbon-containing models like Canopy.
Other Detections
Like Canopy and Santevia, Sprite removed 100% aluminum from our bath water. Copper concentrations also decreased by 11%, but barium increased post-filtration by 6%. Fluoride, phosphorus, and strontium concentrations remained the same.
Since these outcomes are pretty consistent with our other filtered water tests, we believe they’re due to incidental changes to our water quality between testing rather than pointing to an issue with the filter itself. It simply tells us that the filter can’t remove any of these impurities.
Performance Analysis
The Sprite Bath Pure Filter’s flow rate with the slower-flow faucet speed measured at 1.01 GPM, resulting in a score of 8.50. Based on this flow rate, it’d be the fastest of all the filters to fill a 30-gallon bath, with an estimated fill time of just under 30 minutes.
The filter has a majority-plastic build that earned it a lower design score of 6.60. While it does feel well-made, we’re concerned about its long-term durability (especially the plastic hook, which is quite thin), as well as the potential for microplastics or bisphenols leaching from the unit into the filtered water.
It did, however, redeem itself with the same easy setup and maintenance as its competitors. The filter can be attached to most faucets with a tool-free installation and lasts for around 30 baths, earning scores of 9.50 and 9.57, respectively.
Sprite offers a slightly longer 1-year warranty and 45-day money-back guarantee, which is nice and reassuring. Shipping costs vary based on location, resulting in an overall company score of 8.80.
| Criteria | Results |
|---|---|
| Overall Score | 8.00 |
| Health Related Contaminants | 7.70 |
| Aesthetic Related Contaminants | 8.00 |
| Performance Certification | Not Certified |
| Filtration Rate | 1.01 GPM |
| Component Quality | Weak |
| Component Certification | Unsatisfactory |
| Setup | Outstanding |
| Servicing Requirements | Outstanding |
| Costs | $0.022/ gallon |
| Warranty Length | 1 year |
| Shipping | Variable Shipping Costs |
| Returns | 45 days, in original unused condition |
Crystal Quest Bath Ball Filter
The Crystal Quest Bath Ball Filter is another “traditional” take on a bath filter, with a cylindrical unit containing GAC (granular activated carbon), redox (KDF), and chlorine removal (possibly calcium sulfite) filtration media that hangs beneath the faucet spout. It performed very similarly to Sprite in our testing, but its poor returns policy resulted in a slightly lower score overall.
What We Like
Product Specs
| Price | $64.95 |
| Contaminants Reduced | Chlorine |
| Certifications | Not Certified |
| Process | Calcium Sulfite + Activated Carbon + KDF |
| Filter Capacity | 2,500 gallons |
| Annual Cost | ~$80 |
| Warranty | 1 year |
Specs
The main unit is made from ABS plastic, with the filter cartridge made from polypropylene, polyethylene, and polyolefin (all BPA-free). The filter is claimed to reduce “pollutants and contaminants”, including chlorine and common disinfection byproducts, and is sold in 5 colors: the more conventional white, chrome, and black, as well as pink and blue.
All colors cost around $65, putting Crystal Quest behind Canopy as the second-most expensive bath filter we tested. Given that its performance was worse than Santevia’s (our top pick, which costs just $20), you may find it hard to justify the upfront cost. However, the filter does have a long projected lifespan of 12 to 18 months, so at least you should (in theory) get plenty of use out of it before you need to replace the cartridge.
Contaminant Reduction Testing
The Crystal Quest Bath Ball filter performed slightly worse than Canopy and Sprite in our contaminant reduction testing, resulting in a lower score of 7.45 in this category.
Chlorine
Here’s a breakdown of our data from the two chlorine reduction flow tests:
- In our “fast flow” test (with an average flow rate of 3.79 GPM), the filter didn’t remove any chlorine. This is a really poor result and what ultimately brought its score down below Sprite and Canopy.
- In our “slow flow” test (with an average flow rate of 0.97 GPM), the filter brought chlorine levels down from 2 PPM to 0.3 PPM (an 85% reduction)—still not great, especially given the impracticality of actually filtering an entire bath full of water at this slower speed.
Crystal Quest was the worst-performing of all the products we tested when it came to chlorine reduction, being the only filter that wasn’t capable of removing 100% chlorine at the slower faucet flow. So, not only does it have a longer fill time (we estimated 31 minutes for a 30-gallon bath), but the filter didn’t even perform as intended.
The Crystal Quest Bath Ball Filter has been tested by IAPMO R&T Lab (a division of the IAPMO Group) to NSF/ANSI 177 for chlorine reduction, but it’s not officially certified. The lab results show that at a maximum flow rate of 0.5 GPM, the filter removed an average of 62-66% of chlorine, similar to our own test findings.
Hardness
Total hardness increased by just over 8% after filtering our water using the Crystal Quest unit. Carbonate increased by 41%, magnesium by nearly 19%, and calcium by 8.5%, suggesting some influence from the “chlorine removal” media.
The pH of our water increased from 7.2 to 7.3, and TDS increased by just 2%.
DBPs
We had high hopes that the Crystal Quest filter would be capable of removing disinfection byproducts, given that this is actually claimed by the manufacturer. Specifically, chloroform (the DBP detected in our water) is listed as something that the Bath Ball Filter can remove.
But in our own water tests, our data actually shows a 4.45% increase in chloroform, demonstrating that (in our circumstances at least) the filter can’t remove disinfection byproducts at all. We could find no testing, either by the manufacturer or a third-party lab, to validate these claims.
Crystal Quest claims that the filter offers “the most advanced filtration process on the market”, yet it was one of the poorest-performing bath tub filters of all those we tested for contaminant reduction.
Other Detections
Aluminum was eliminated by 100% with the Crystal Quest bath filter, while barium increased by 10%, fluoride, by 20%, and strontium by 5%. Phosphorus concentrations remained the same, but copper increased by 52%, likely due to leaking from the KDF filter media.
Our Hands-On Tests
The Crystal Quest Bath Ball Filter had a flow rate of 0.97 GPM at the slower faucet flow, receiving a score of 8.50 in this category.
It had one of the poorest designs of all the bathtub filters, with flimsy plastic components that left us questioning its overall component quality, resulting in the lowest design score we’ve awarded so far: 6.60. But it was, at least, easy to hang from our faucet, receiving a high setup score of 9.50.
The filter also has a simple, affordable maintenance schedule. It reportedly lasts 12 to 18 months and needs replacing after filtering 2,000-2,500 gallons of water, contributing to its maintenance score of 9.75.
Crystal Quest’s 1-year warranty rivals Sprite’s and Canopy’s, but you’ll only get free shipping on orders over $150, and returns for refunds are accepted ONLY on perfectly new, unused items in the original packaging, pulling down the company score to 8.05.
| Criteria | Results |
|---|---|
| Overall Score | 7.94 |
| Health Related Contaminants | 7.70 |
| Aesthetic Related Contaminants | 6.00 |
| Performance Certification | Not Certified |
| Filtration Rate | 0.97 GPM |
| Component Quality | Weak |
| Component Certification | Unsatisfactory |
| Setup | Outstanding |
| Servicing Requirements | Outstanding |
| Costs | $0.016/ gallon |
| Warranty Length | 1 year |
| Shipping | Free on orders > $150 |
| Returns | Only on perfectly new & unused items |
Tubo Bath Filter
The Tubo 2.0 Bath Filter was the poorest-performing bath filter we tested, securing the lowest weighted score behind Crystal Quest. It’s marketed towards parents who want to give their babies and children safe, gentle baths, with an 8-stage filter that’s said to reduce skin dryness and irritation.
What We Like
Product Specs
| Price | $64.99 |
| Contaminants Reduced | Chlorine |
| Certifications | Not Certified |
| Process | Calcium Sulfite + Activated Carbon + KDF |
| Filter Capacity | 2,500 gallons |
| Annual Cost | ~$70 |
| Warranty | 60 days, Lifetime for an extra $5 |
Specs
The Tubo filter is sold in just one design (white and chrome) and costs $65; the same as Crystal Quest (although you can save by buying two or three filters in bulk). Also like Crystal Quest, the filter lifespan is around 2,500 gallons, although Tubo suggests replacing it more regularly, every 6 months.
Much of Tubo’s marketing lingo is misleading and deceptive. The manufacturer says it “purifies” bath water, which suggests it removes all impurities (not true, only purification methods like reverse osmosis and distillation can achieve this). It’s also claimed to eliminate harsh chemicals and contaminants, when our own testing shows that some contaminants were only reduced, and some weren’t addressed at all.
Plus, the filter is said to remove up to 99% of bacteria and viruses, which is a bold claim that’s highly unlikely to be true. The manufacturer is secretive about the exact media used in the 8-stage filter, but even if KDF is used, this medium is simply bacteriostatic (meaning that it inhibits bacterial growth) rather than bactericidal (capable of killing bacteria).
Our Lab Tests
In our contaminant reduction testing, the Tubo Bath filter received a poorer score of 7.45, the same as Crystal Quest.
Chlorine
Here’s how the filter performed across our two chlorine reduction flow tests:
- In our “fast flow” test (with an average flow rate of 3.61 GPM), the filter removed no chlorine whatsoever.
- In our “slow flow” test (with an average flow rate of 0.87 GPM), the filter eliminated 100% chlorine.
Despite doing slightly better than Crystal Quest in the slow flow test, Tubo’s performance was evaluated based on its inability to remove chlorine in the fast flow test, which is why the two received the same contaminant reduction scores. Most folks will be unwilling to take the slow flow approach (based on our flow rate testing, we calculate it’ll take around 34 minutes to fill a 30-gallon bath) in order to guarantee chlorine removal.
Tubo says its bath filter is “clinically tested”, but we could find no third-party test data on the website—this is especially disappointing given the extent of Tubo’s contaminant reduction claims.
Hardness
Our results show minimal difference in total hardness (an 8% increase), carbonate (a 17% decrease), magnesium (a 3% increase), and calcium (a 10% increase) post-filtration, telling us that the Tubo Bath Filter has minimal effect on these parameters.
The pH of our water reduced slightly from 7.2 to 7.1, and TDS increased by 10%.
We also saw a 405% increase in copper post-filtration, from 0.0017 to 0.0086, suggesting that the filter uses a copper-zinc KDF media, which is introducing copper into the filtered water.
DBPs
Despite its other extensive contaminant reduction claims, Tubo doesn’t claim to remove disinfection byproducts, and our test results showed a 2% increase in chloroform post-filtration—disappointing, but not unexpected.
Other Detections
Tubo eliminated aluminum, but we saw a 12% increase in barium and the biggest increase in copper (405%, from 0.0017 to 0.0086) PPM out of all the filters we tested. Concentrations were still within the HGL of 0.3 PPM.
Fluoride and phosphorus concentrations remained the same, while strontium increased by 5%.
Subjective Testing
We measured Tubo’s flow rate at 0.89 GPM in our slow faucet flow test, earning it a score of 8.50, just like the other bath filters we tested.
It presented similar build quality and longevity concerns as Crystal Quest, with its flimsy all-plastic construction, resulting in the same design score of 6.60.
Its redeeming performance categories were setup (earning a 9.50) and maintenance (9.75). The unit simply hooks onto the end of your bath faucet and only requires a filter change after filtering around 2,500 gallons of water, meaning less frequent maintenance than most other models we tested.
Tubo received the poorest company score (7.60) of all the bath filters in this list. You have to spend $85 to get free shipping, and while the 60-day guarantee is decent, you have to pay an extra $5 for the “lifetime guarantee”. Otherwise, the warranty is also just 60 days.
| Criteria | Results |
|---|---|
| Overall Score | 7.91 |
| Health Related Contaminants | 7.70 |
| Aesthetic Related Contaminants | 6.00 |
| Performance Certification | Not Certified |
| Filtration Rate | 0.97 GPM |
| Component Quality | Weak |
| Component Certification | Unsatisfactory |
| Setup | Outstanding |
| Servicing Requirements | Outstanding |
| Costs | $0.014/gallon |
| Warranty Length | 60 days, Lifetime for an extra $5 |
| Shipping | $85 for free shipping |
| Returns | 60 days |
Final Thoughts
While the Santevia Bath Filter was the standout among the bath water filters we tested, none of the products blew us away with their performance. We found that with most filters, you can get great chlorine reduction, but there’s always a trade-off with time.
- If you’re happy to wait 2–4× longer for the tub to fill, most products we tested were able to remove chlorine down to 0.
- If you want to fill your bath at a near-normal speed, Santevia was the only one to reach 0 PPM in our field test—but none of the products reduce DBPs or hardness, as confirmed by our lab data.
It’s worth setting your expectations if you’re interested in buying one of these bath filters. They’re suitable for reducing chlorine, but they’re not solutions for hardness or DBP removal. If you are concerned about water hardness, you’ll need to use a proven technology like cation exchange water softening.