ProMax Under Counter Water Filter

(10 customer reviews)
SKU: PMC-400 Categories: ,

Designed to be installed under counter with a separate faucet or inline with the water supply line.


-Single-stage design (optional dual stage)
-Premium quality ABS housing and fittings
-BPA & BPS free
-Mounting bracket, 3/8” quick connect fittings, 6’ pc of 3/8” polyethylene tubing, wrench, and chrome plated lead-free faucet kit included
-ProMaxTM “all-in-one” water filter technology
-No electricity required
-Easy to replace filter element
-Overall size is 4.5″ x 13″
-Replacement Filter: PMC-34RF


Optional Faucet:

Chrome finish
Flip-up handle for continuous use
Push down handle for water on demand


ProOne® Under Counter Water Filtration System w/ ProMaxTM filter technology. Helps reduce/remove a broad range of over 200 contaminants including VOCs, lead, fluoride, heavy metals, pesticides, SVC’s, disinfectants, inorganic non-metallics, herbicides, pharmaceuticals, PFOA, PFOS, and microplastics. Tested to NSF/ANSI-42 & 53 standards. See ProMaxTM Lab Report for details.


ProMaxTM  Under Counter Specifications:

-Type of installation: Under Counter
-Maximum Working Pressure: 860 Kpa (125 psig)
-Minimum Working Pressure: 137 Kpa (20 psig)
-Maximum Working Temperature: 38° C (100° F)
-Minimum Working Temperature: 5° C (41° F)
-Recommended Flow Rate: 0.2 – 1.0 gpm
-Contaminant Reduction: Refer to Lab Report
-Filter Life Expectancy: Up to 900 gallons or 1 year
-Replacement filter: PMC34RF


ProMaxTM  Dual Stage:

Stage 1 includes a 5-Micron standard pre-sediment filter which helps protect your new ProOne® filtration system from sediments commonly found in aging water supply pipes. Reduces damaging effects of sediment such as dirt, sand, debris, and rust. Ideal for use with most city or well water.


Stage 2 includes ProMaxTM “all-in-one” filter technology.


Your #1 Choice in Under Counter Water Filters!

ProOne® Water Filters offers affordable water filtration systems to help improve the quality of your water. Dedication to innovation, extensive testing, and exceptional customer service is our commitment to you! Get the Most tested, Most trusted Under counter water filter on the market today!



Click here for lab report

Click here for instructions

Click here for filter technology comparison chart

Weight N/A

Single Stage, Dual Stage

Faucet Options

With Faucet, Without Faucet


10 reviews for ProMax Under Counter Water Filter

  1. Elizabeth Miranda Monterrosa (verified owner)

    We used the gravity filters for years, which worked but were very large for our counters. I was tired of looking at it and bought this instead. Great idea. Works amazingly. Takes up no space. We got the sediment filter as we live in Central America and the sediment is heavy to the point of clogging faucets at times. The sediment filter works like a charm. No complaints except that I wish I had bought sooner. The gravity filter still gets used occasionally and the pitcher travels with us. So we’re still making good use of all our propur products. And I recommend them all to everyone all the time.

  2. Gareth Quiggan

    Absolutely excellent filter, great taste and very thorough. Bought one for each bathroom in my house and for my daughter’s new home. We’re now in our third year of using them with zero problems and great performance. Easy to install and easy to maintain. My family is very happy knowing that we are drinking the safest water possible, as our ProMax removes hundreds of contaminants while leaving all of the important minerals and nutrients in place and producing ph., neutral water. I highly recommend ProOne filters: they are absolutely unsurpassed.

  3. Lorri Vogel

    After much research landed on ProOne for the effectiveness of their filters. I have had it for several years and replaced the filter yearly. I am so satisfied with the quality of water it produces.

  4. Liesl (verified owner)

    Upgraded from a gravity fed filter to this under the sink one. So convenient to have this right at the sink and saves counter space. I was able to hook up the ice maker from the refrigerator to this filter as well. The staff is knowledgeable and was able to answer my questions about hooking the filter up correctly and which filter to buy since I have wanted to remove fluoride. Super happy with this filter.

  5. Kelly Trimmer

    We just converted from an RO system to the ProOne Under Counter filter. After researching the many water filters on the market, I determined that the ProOne ProMax system was the best at removing the widest range of potentially harmful contaminants from our drinking water, and unlike most others, it’s performance is documented by an independent 3rd party lab. The installation was easy, and I now have only one filter to change once a year. Plus, the water tastes better than it did with our RO system. Couldn’t be happier!

  6. Marie (verified owner)

    I love this RO system so much, i bought one for my son. The water is so tasty and healthy at last. I got so tired of being scammed by water companies with their expensive filters gimmicks. I moved to a different state and could not even moved the old RO system with me since it was so useless and i could not replace the filter myself since it could only done by the local company. I lost $800. I am so grateful to ProOne! thanks!

  7. jphunts

    I found this to be the best filter system on the market. I find it comforting that an independent lab report certifies this system removes the contaminants that are in my municipal water. On top of this, my water now tastes like water with no chlorine or foreign taste. I understand this filter doesn’t filter out much needed minerals needed for good health, another plus. I’ve used this system for years. The best part is customer service at ProOne is ten stars!

  8. Julie McCoy

    I absolutely LOVE being able to wash produce in clean water. This has been a game changer in our house. We bought a filter for the fridge too, but we go to this all the time. So happy with our purchase. Also, Customer service is great. I needed an extra metal fitting when installing one of the filters and they shipped it free of charge. Much appreciated, ProOne!

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