Waterdrop MNR35 Remineralization Filter Compatible with Undersink RO System

Pros ✅ Improves taste significantly Many users report that RO water tastes "flat" before adding the MNR35 and more like spring water afterward. Reviews consistently mention a noticeable improvement in flavor. ✅ Adds minerals back to RO water The filter is designed to reintroduce minerals such as calcium, magnesium, potassium, and small amounts of sodium after the RO membrane removes most dissolved solids. ✅ Easy installation The 1/4" quick-connect fittings make installation straightforward for most under-sink RO systems. Many reviewers describe it as a simple DIY upgrade. ✅ Long filter life Rated for approximately 9–12 months or about 1,100 gallons of treated water.

Great flavor. Adds about 40ppm TDS to the RO water coming out of my membrane stage. Really helps with that harsh RO taste. It was very easy to hook up and no leaks.

I mainly picked this up for my coffee—everything from espresso and V60 to doing "soup" extractions with the OXO brewer. I looked around at a bunch of options and found that most remineralization filters are either too basic, adding only calcium, or they go way overboard and add too much. This one hits a great middle ground; my final TDS sits right around 30–40, which makes the water taste good without being too heavy. I also added a bypass line so I can still get pure RO water when I want to mix my own specific water recipes from scratch, giving me the best of both worlds. It’s a solid, balanced setup if you want good drinking water.

Easy to install, works well, water has a nice taste.

The filter does work as intended in introducing minerals back into the RO water. However I feel that it's lifespan is very short. After about 3 months of I'd consider normal water use. It drastically losses it's ability to replenish the water with minerals. At least it does show my RO system works well as without this additional filter. My water taste very "flat", fresh and clean but, akin to distilled almost. Which is good for what you'd expect from the RO system. However for consumption. Drinking pure RO water without re adding essential minerals back into it is not advisable for long-term health. So while this does indeed work, it loses its effectiveness rather quickly. So it is a costly replacement in the long run. I would like for Waterdrop to at least make this filter last longer. A bit larger in size or something. Otherwise. Good item.

Was very easy to install, it will make my fridge water a lot better.

Got tired of the flat taste from my RO unit. Plumbed this in three months ago. Water tastes normal now, not empty. Wish Waterdrop just built this directly into the main system instead of making me mount a separate tube. Worth knowing: You will need a small utility knife to cut your existing RO tubing cleanly before pushing it into the quick-connect ports.

Easy install, water tastes better than without. I also received superb support from Waterdrop customer service (Harper)! Waterdrop is a really good company, I've always been impressed by how support their products after purchase. I own three different RO units for various properties and I love them!

Very effective in improving TDS. Improved TDS from 8 to 45. Was delivered ahead of time.

La remineralizzazione funziona bene, l’acqua è buonissima, leggera, sapore gradevole (prima bevevo acqua sant’anna/san bernardo)

Es de los mejores que se consigue en mexico, aumenta los TDS.

Ce petit filtre de reminéralisation est vraiment top ! Il donne un goût excellent, doux et très agréable à l'eau, je le recommande sans hésiter. De plus, un grand merci au vendeur car tout est arrivé exactement dans les temps, super bien emballé et conforme. Une expérience parfaite pour ce produit !

I highly recommend this product. I used the Waterdrop G3P800 for a week without the reminerilization, and it is excellent, very much like distilled water, with no discernible taste. Despite this, it is very hydrating. After reviewing all the comments regarding systems similar to mine, I decided to acquire the remineralizer. It was quite simple to install; perhaps I could have optimized its placement, is installed for functionality over astetics, but overall, the water quality is superior to any bottled water I have ever purchased, even surpassing the artesian well water from my grandmothers. I am truly impressed. Previously, I would purchase large bottles of mineral water for my water cooler/hot water dispenser. I have since returned nine out of ten of those water jugs and bottles, keeping just one to refill. The filter has filled this large bottle seven times since its purchase. Furthermore, all our food is now cooked with RO water, and the taste is superb. Noodles, in particular, taste much better, as do any foods that absorb water, such as potatoes and vegetables. In essence, I use it for anything that involves ingestion into my body, whether liquids, food, or for hydration. I also have 2 professional water testers, one for PH, and the other measures the rest, an all in one tester, I reviewed in another post on Amazon. I wholeheartedly recommend the entire system; the remineralization component is invaluable in completing the setup.