









💧 Elevate your hydration game with Brondell’s premium RO membrane—because clean water waits for no one.
The Brondell RF-40 is a WQA-certified reverse osmosis membrane filter designed for the Circle Under Sink RO system. It effectively reduces 64 contaminants including heavy metals, fluoride, and industrial chemicals, delivering superior water quality. With a 24-month lifespan and easy DIY twist-and-seal installation, it features a built-in change indicator and replacement battery for hassle-free maintenance. Engineered for sustainability, this filter ensures your home enjoys consistently pure water while supporting eco-friendly living.






| ASIN | B012UPEAQM |
| Best Sellers Rank | #13,900 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #119 in Replacement Under-Sink Water Filters |
| Brand | Brondell |
| Compatible Water Purifier Models | Brondell Circle RC |
| Customer Reviews | 4.5 4.5 out of 5 stars (751) |
| Date First Available | July 29, 2015 |
| External Testing Certification | WQA |
| Is Discontinued By Manufacturer | No |
| Item Weight | 1.2 pounds |
| Item model number | RF-40 |
| Manufacture Year | 2021 |
| Manufacturer | Brondell |
| Material | Plastic |
| Number of Items | 1 |
| Product Benefits | Removes Pollutants |
| Product Dimensions | 2.75"D x 2.75"W x 11.25"H |
| UPC | 819911013616 |
| Unit Count | 1.00 Count |
J**N
Delivered WET? Don't freak out.
So, this is the first time I have had to replace my Brondell Reverse Osmosis filter. I have replaced the other pre/post filters twice and now it' was time to change the RO element. I always dread this part of the cycle on RO systems because it is EXPENSIVE.....but this is how these systems work and deliver clean water. I previously had a GE system... and I used to operate an RO system on our boat (to turn sea water into drinking water). Having dealt with the pre and post filter set several times I noted that these filter come in a box, are individually wrapped and sealed, and are DRY. This time I noted that the RO element seemed heavier. It was in a sealed box and was individually sealed in a pouch as well. When I opened it and took of the cap, liquid dripped out. Initially I was worried that someone had returned a used filter and Amazon sent it back out to me. Even though it seemed to be sealed I wouldn't put it past a dishonest person to run this back through a bag sealer and return it for the $100 bucks. Then I remembered from my boating days that Reverse Osmosis membranes have to stay wet. When they go for an extended time of no use they must be "pickled" or BRINED in a special storage fluid. I was starting to think these are no different. I hooked it all up, drained the system per the instructions, and tested the water. I was horrified to see that it was producing water that had 290 PPM (parts per million) of TDS (total disolved solids). The water out of the tap was 513 PPM. The water out of my 2 year old RO filter was 80PPM. This was horrible. So, thinking that I might have gotten a used filter, I sent an email to Brondell support. As I waited for a response I decided to run the system through several more flush cycles. This involves running the water out of the resevoir tank until it's empty, then allowing it to refill (about a 1 hour process). Low-and-behold, each flush revealed a slightly better water test. After I erformed a total of 8 flushes, the Brodell Circle system with all new filters is producing water at about 40PPM TDS. For a reference, good bottled drinking water is about 20-25 ppm TDS. I'm happy with this. After a few days passed I got a response from Brondell support. The verified that the RO filters are indeed shipped wet/brined. They were surpised that it toon so many flush cycles to get to 40PPm.... but I feel SO much better knowing that I am not drinking from someone else's rotten recylcled filter. I f YOU get a wet RO filter.. and the box seal is in place and the wrapper bag is intact... DON'T freak out. This is how it is supposed to be. BRONDELL.... it might be a good idea to print this on the RO filter box somewhere to allay customer fears (especially since the other 3 filters are shipped dry). The Brondell Circle is a great system. It is so much simpler and the filter cycle and change procedure is indeed much easier that other systems I have had. I feel well assured that the water we are drinking and making coffee from is the best we can get.
J**K
Satisfied
I got what I ordered
V**R
Pure Clean Water
Great quality filter. As part of a 4 filter system, this definitely keeps your water purified. Great quality, doesn’t leak, extremely easy and simple to install. Highly recommend this brand.
S**Q
Great but the price , not so great!
I give it a 5 for being a great product . However, the price is too high and has increased over the last 6 years. We bought it for health purposes and to save money from buying purified water. But the price is truly high.
J**P
Good quality but expensive
Good quality and perfect fit when replacing them but only one seller with high prices
J**H
Circle RO replacement filter.
A vital part of our Circle water system. Thanks for having this in stock!
J**E
Very Expensive
Clean drinking water at home is very important to me, and I like the quality of the filtered water. It gives me peace of mind knowing the water tastes clean and well filtered. However, in my experience the filter is extremely expensive for something that should last about two years. After some months, the water flow becomes very slow and it takes much longer just to fill a glass. Because of the high price, I expected it to last longer without losing pressure.
X**G
Good
Clarity
T**E
Bondell is the best
L**E
RO system…does great job of filtering our water
A**R
Super
Y**S
Filter was used before!! I found full of water inside when open cup, water still going out the filter. Shame on you, fraud!!!
Trustpilot
2 days ago
2 weeks ago