If you are in the market for a high-end under the sink water filter then the Aquasana AQ-5300+ should be on your radar. This is a top-rated water filter of 2020 with a high-flow design, three-stage filtering, and all the NSF certifications that you are looking for.
April 2021 Update: After about 6 months of excellent performance the filters needed to be replaced. I swapped out the old filters for the replacement filter set and was immediately met with two leaks in the filter system despite having no leaks before the change.
Having spent a lot of time troubleshooting the filter, I could see that the filter housing (the sump) was leaking and the large o-ring on one of the housings was worn out. The same thing seemed to happen to an o-ring that connected the top piece of the sump to the filter housing. These were slow leaks (a few drips a minute) but enough to be a problem.
Leaking after the filter filter change seems to be a common problem with these Aquasana filters. The correct fix is to stop using the filter, contact Aquasana, and request replacement o-rings for the leaking parts.
Aquasana AQ-5300 Basics
The specific model I purchased and use in my home is often sold as the “Aquasana AQ-5300+.55 3-Stage Max Flow Under Sink Water Filter” but Aquasana sells it as the “Claryum 3-Stage Max Flow” water filter and the common name is the “AQ-5300+”.
The Max-Flow is the high-flow rate version that uses larger filters than standard, while the normal model is the “Aquasana 3-Stage Under Sink Water Filter System” or, more commonly, the “Claryum 3-Stage” or “AQ-5300.”
The entry level model in the line is the Aquasana 2-stage Filter (AQ-5200) which has a slower flow rate and less filtering capability but still maintains the important NSF certifications and is still a highly capable filter.
The names get a little confusing so here is how you keep things straight…
- AQ-5300+: High-flow rate, 3-stage filtration, under the sink filter, sold with a faucet
- AQ-5300: 3-stage filtration, under the sink sold, with a faucet
- AQ-5200: 2-stage filtration, under the sink, sold with a faucet
If you are buying online, you might notice the model is prepended with a number, making fro something like “AQ-5300+.55”. The numbers at the end correspond to the finish of the faucet you are getting:
- AQ-5300+.55: Brushed
- AQ-5300+.56: Chrome
- AQ-5300+.62: Oil-rubbed bronze
If you are an apartment dweller, a renter, or just don’t want a dedicated faucet for your filtered water, you can filter your cold water with the Aquasana Claryum Direct Connect, which is a single-stage filter which flows water through your existing faucet for just the cold water. This one has limited flow rate and not much capacity but it’ll get great water quality to any faucet with minimum work.
What Does It Filter?
The AQ-5300+ has NSF 42, 53, and 401 certifications. NSF 42 filters for water taste while NSF 53 filters for safety. 401 is a newer specification that is for “emerging” compounds, like, herbicides, pesticides, and pharmaceuticals.
This means that the AQ series water filters have the important certifications that you need in a good water filter. In my opinion you should accept no substitute these these certifications and no explanation from a company has convinced me otherwise.
These filters will remove…
- Cysts (for example cryptosporidium)
…plus a number of other minerals and compounds.
Aquasana AQ-5300+ Installation
The Aquasana water filter installation isn’t a particularly difficult job and it’s something that most reasonably handy people will be able to do on their own without any real problems. If you aren’t comfortable working with water or things like compression fittings you should consult a professional plumber, but the job isn’t too difficult if you are patient and follow the directions closely.
Aquasana says the installation should take about 45 minutes, but it took me about twice that thanks to some tough stainless steel under the sink (which meant mounting was a pain) and because I had some trouble with the tubing inserts in the water filter holder (the sump). Having done the job once I know the next time would be much, much easier.
Overall I would rate the installation as being a 5 out of 10 in terms of difficulty, with most of the challenges being a result of working with the compression fittings. The instructions are OK, but not great. If you want an easier installation I’d recommend the Filtrete High Performance Drinking Water System (4US-MAXL-S01) which has better instructions and easier to use fittings. Unfortunately the Filtrete systems aren’t as good filters as Aquasana’s.
The AQ-5300+ use the AQ-5300+R filter set. It sells or about $65 and is good for 800 gallons of water and 6 months. The filters are easy to find online or can be purchased directly from Aquasana.
The AQ-5300+ set includes a tool for removing the filters from the housing as well as a battery alert that will beep when the filters need to be replaced.
Water Taste and Peformance
Once the filter is installed I was very happy with the Aquasana AQ-5300+. The flow rate through the included faucet is good, enough to fill a glass of water in a moment or eventually fill a pot for soup. It’s not fast, but it’s not meant to be fast.
I measure the water performance at about 0.5 gallon per minute with new filters. The 3-stage high-flow model I own is actually rated for 0.72 gallons per minute, so mine definitely ran slow. This could be due to my water pressure, which is normal, but not high. Regardless, you won’t get a lot of water volume out of the included faucet as it’s optimal for drinking water but slow if you want to fill a pot for boiling beans in or cooking pasta.
The water tastes very clean, with no real mineral flavor. A NSF 42 filter will definitely remove most of the character from your water, but it will leave it tasting fresh and clean, though indistinct. To me the water tastes quite good, but I wouldn’t consider myself to be particularly picky in this regard. I did some research online and almost people seems to like the taste of their AQ-5300 filtered water.
Aquasana AQ-5300+ Closing Thoughts
The Aquasana AQ-5300+.55 3-Stage under the sink filter I purchased wasn’t cheap — street price is about $175 — but I’m confident about the quality of the water and I’m happy with the installation job. It’s not as easy to install as some of the competition, but it really wasn’t too bad. And then the certifications are top-notch, which was of primary importance to me.
I purchases the 3-stage max-flow unite with the thoughts that I never wanted the water to get too slow, because that’s an issue with my Filtrete water filter. That said, the filtered water speed isn’t too fast to begin with, so most people are probably fine with the standard AQ-5300 filter. This unit is cheaper and smaller, so it’ll take up less space under your sink.
Depending on where you live you could even go with the 2-stage filter, which doesn’t have the pre-filter. This means the overall capacity of the system will drop by about 100 gallons over the course of the 6-month life and your flow rate will drop if you live in a high-sediment area. This model, the AQ-5200, will be fine for most people but savings in size and cost didn’t make a huge difference to me, so I’m happy I opted for the AQ-5300+, even though I now know the improvements for me were negligible.
- What is NSF 42 certification for water filters?
NSF 42 (technically NSF/ANSI 42) is a certification for water treatment units (basically water filters, that concerns “aesthetic effects” or how the water tastes. A NSF 42 filter will remove odors, chlorine, iron, sediment, zinc and other materials. It will also lower the “TDS” or total dissolved solids in the water. It is not designed to remove lead, mercury, or hazardous substances.
- What is NSF 53 certification for water filters?
NSF/ANSI 53 is a certification for water treatment units (basically water filters) that concerns unhealthy substances in the water. An NSF 53 filter will remove essentially all of these substances from drinking water. One 50 minerals and compounds are covered, with the most prominent being lead, mercury, VOCs (volatile organic compounds), and asbestos.
- What is NSF 58 and why doesn't the Aquasana filter have it?
NSF/ANSI 58 certification is only for reverse osmosis (RO) water filters. The Aquasana AQ-5300 line is not a reverse osmosis system. Aquasana does sell an RO system, which is the OptimH2O Reverse Osmosis + Claryum filter.