Circle Reverse Osmosis Under Counter Water Filtration System

SKU: RC100
Regular price $449.99
In stock
On backorder
Faucet Finish
Free shipping on orders over $50
Authorized dealer — all brands
NSF certified systems available

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The Circle Reverse Osmosis Under Counter Water Filtration System delivers pure, great-tasting water using patented smart water-saving technology that is up to 10 times more efficient than conventional RO systems—with 10× less wastewater. WQA Gold Seal certified to NSF/ANSI Standards 42, 53, 58, and 372.

  • Reduces over 60 contaminants including lead, chlorine, VOCs, and more
  • Four-stage filtration: sediment, pre-carbon, RO membrane, post-carbon
  • Flexible storage tank with 1.6-gallon (6.0 L) capacity
  • Automatic membrane flushing extends filter lifespan
  • Designer polished chrome faucet with LED filter-change indicator
  • Operates without electricity — rapid refill rate
  • Compact design: 13.8″L × 9.25″W × 16.5″H, 14.6 lbs
  • DIY installation; free shipping to contiguous US and Canada
  • Filter replacement schedule: pre/post-carbon every 6 months, membrane every 24 months
  • 1-year limited warranty with US-based customer service
  • Filtration Stages 4
  • Filter Technology Sediment, pre-carbon, RO membrane, post-carbon
  • Contaminants Removed Reduces 60+ contaminants including chlorine, lead, fluoride, arsenic, barium, benzene, cadmium, copper, cysts, endrin, hexavalent chromium, methoxychlor, pentavalent arsenic, radium, trihalomethanes, atrazine, and VOCs
  • NSF Certifications
    • NSF/ANSI 42
    • NSF/ANSI 53
    • NSF/ANSI 58
    • NSF/ANSI 372
  • Lead Free
  • Dimensions 13.8" L × 9.25" W × 16.5" H
  • Filter Life Sediment/carbon: 6 months; Membrane: 24 months
  • Replacement Filter SKU RF20 (sediment/carbon), RF40 (membrane)
  • Replacement Interval RF20 every 6 months; RF40 every 24 months
  • Included in Box T-valve (3/8" all-metal with rubber washer), T-valve adapters (3/8" to 1/2"), drain clamp, chrome faucet with LED filter-change indicator

Free shipping on orders over $50. Most orders ship within 1–2 business days directly from our authorized suppliers. You'll receive tracking information via email.

Need it faster? Contact us for expedited shipping options: contact@reinwaterusa.com

All under-sink water filtration systems sold by Rein Water USA include manufacturer warranty. Crystal Quest systems carry a limited warranty — see product listing for terms. Brondell systems include a 1-year limited warranty on parts and labor, excluding consumable filters.

To make a warranty claim, contact contact@reinwaterusa.com with your order number and proof of purchase.

Customer Reviews

4.91 out of 5 (66 reviews)

Reviews collected on Reviews collected on brondell.com (the manufacturer's website), shown with permission.

★★★★☆

Two more years. .

Dependable. The filters were easy to replace. The flow is very slow but it's been working for 2 years and I am dealing with it as a low volume user.

CHRISTINA S.✓ Verified Buyer2026-05-26
★★★★★

I love 💗 my Brondel

I love 💗 my Brondel equipment

SHERRY K.✓ Verified Buyer2026-05-15
★★★★★

Great product

Great product

MICHAEL B.✓ Verified Buyer2026-02-26
★★★★★

Great

Easy replant installation!

Zach W.✓ Verified Buyer2025-11-08
★★★★☆

Filter good, faucet misleading and not so good.

I believe it is good maybe great product. The only thing I would like to see is a lower cost of replacement filters. The only problem overall has been the tap/faucet stop recording the time. It still works without fail to open and close just no need to replace battery it goes into replacement mode right away. I can still remember to change it at the recommended time and that is all it really did; it's not like the thing actually checked to quality of the water or anything like that. It just timed it and from what I can see there isn't even a meter to read how much water has gone through the filter. So, I just change it every six months as they recommend and save the cost of a new faucet.

Robert F.✓ Verified Buyer2025-08-26
★★★★★

I like it and it’s

I like it and it’s very good service

Hratch K.✓ Verified Buyer2025-08-23
Show 14 more reviews
★★★★★

Best System Ever

I have this Circle unit for 5 years, it’s the best system I’ve ever had and I have had a system in my house for over 20 years. Circle has the easiest filters to replace and there is no tank to run out and wait for it to refill. The only issue I have is the replacement filters never go on sale and can’t be purchased from any wholesale outlet. Mike

MICHAEL P.✓ Verified Buyer2025-05-06
★★★★★

We purchased the Brondell for

We purchased the Brondell for our own health but little did we know it is helping our 17 year old chihuahua. We rescued her and recently took her to the Veterinarian for her annual checkup. The Veterinarian said her levels were lower on her kidneys and asked us what we were doing. I mentioned what her feeding program was which didn’t change and the Brondell water system. He said just keep doing what you’re doing she looks good.

Diana V.✓ Verified Buyer2025-04-08
★★★★★

works

filter for replacement

Praphulla K.✓ Verified Buyer2025-04-03
★★★★★

Excellent

All is good so far . The lady helped me to place the order was very professional and helpful. Good company !!

Fariba H.✓ Verified Buyer2025-01-22
★★★★★

it was good

it was good

joseph b.✓ Verified Buyer2024-10-31
★★★★★

Taste good, perfect system work.

Taste good, perfect system work.

RAE P.✓ Verified Buyer2024-10-11
★★★★★

Well designed

When a product is designed well it is easy to use, replace and it preforms perfectly. I appreciate Brondell for being designed well.

Michael H.✓ Verified Buyer2024-08-31
★★★★★

Makes the taste of the

Makes the taste of the water a lot better. Membrane is easy to replace and maintenance is great since you only have to replace it every 24 months. The cost outweighs buying the water from the store. I also test the PPM of the water with my tester every month and the rating is almost excellent!

Roberto A.✓ Verified Buyer2024-07-11
★★★★★

Easy Cartridge Replacement

Very easy installation of new cartridges. I only have trouble with the battery. It doesn’t seem to work for me. But I change filters by the installation date. That works well for us.

John P.✓ Verified Buyer2024-03-22
★★★★★

We’ve enjoyed our filter, and

We’ve enjoyed our filter, and the fresh water.

Daniel W.✓ Verified Buyer2024-03-18
★★★★★

Though the filters are expensive,

Though the filters are expensive, especially the membrane (which we changed for the first time in four years), they are easy to change, and the taste, in our opinion, is even better than bottled water, which now tastes off to us. We take our own water with us wherever we go.

Roy F.✓ Verified Buyer2024-03-09
★★★★★

Noticeable good taste

Does make a difference of the taste in the water. Enjoying the water preferring it over bottled water.

Peter C.✓ Verified Buyer2024-02-06
★★★★★

Always change filters on time!

Also replace the main filter as well as the three-pack! If you can afford it, I recommend having a full set available so you don't procrastinate on changing the filters on time!

Elizabeth Y.✓ Verified Buyer2024-01-20
★★★★★

water tastes great

water tastes great

AZAM K.✓ Verified Buyer2024-01-17