

💧 Elevate your hydration game with mineral-rich, perfectly balanced water!
The iSpring FA15 is a 10-inch, NSF-certified alkaline inline water filter cartridge designed to upgrade any reverse osmosis system. Featuring a 3-layer filtration with mineral balls, calcite, and corosex, it restores essential minerals and balances pH to transform acidic RO water into refreshing, mineral-rich hydration. Its 1/4” quick connect fitting ensures fast, tool-free installation, making it the go-to add-on for health-conscious professionals seeking superior water quality.





| ASIN | B00FBLGD1S |
| Best Sellers Rank | #1,631 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #12 in Replacement Under-Sink Water Filters |
| Brand Name | iSpring |
| Customer Reviews | 4.4 4.4 out of 5 stars (1,906) |
| External Testing Certification | ANSI |
| Global Trade Identification Number | 00662425063543 |
| Included Components | water filters |
| Item Dimensions D x W x H | 2"D x 2"W x 10"H |
| Item Type Name | iSpring FA15 10-inch Inline Quick Connect 3-Layer Alkaline Replacement Water Filter Cartridge with Mineral balls, Calcite, and Corosex for Reverse Osmosis RO System |
| Item Weight | 1 Ounces |
| Manufacturer | iSpring |
| Manufacturer Part Number | FA15 |
| Material Type | Mineral Balls, Calcite, Corosex |
| Model Number | c8b999bb-ef40-4965-bd04-b8b06a0346fc |
| Number of Items | 1 |
| Product Benefits | Balances pH and restores essential minerals like calcium, magnesium, and potassium |
| Set Name | iSpring FA15 Alkaline Water Filter Set |
| UPC | 662425063543 662425077700 |
| Unit Count | 1.0 Count |
O**Y
It's perfect? 3 Tips provided.
Tip 1: Flow arrow is a clear engraving and easy to miss. Don't rely on the sticker label orientation in comparison to the video, which some say can be reversed. Tip 2: My TDS went from about 10-15 (iirc) to about 50-65 (My tap is 400TDS). Perfect for me. This TDS tastes great to me. EDIT: placing in front of tank, TDS dropped to 30-35. Not sure if this will cause scaling in the tank though. Tip 3: Took me about 1 minute to install. It's easy if you know how to release the quick connect. I did it in-line to the tank for now, but understanding there's maybe a few oz in the cartridge that will sit and overmineralize. I'll move it to before the tank if it bothers us as it does for some others. EDIT: I've heard of 3 different ways in the reviews to install this alkaline cartridge lol. The 3rd way is after tank but before polisher. Just different tradeoffs. No one has provided an argument for which is definitively best.
B**P
Great remineralizer
This worked great but only after I flushed the system 3 times. I also changed the other 3 carbon and debris filters too so it could have been those too. After the 3 flushings, the water was excellent tasting! I used this instead filter instead of the apex one on my roes ph75. No issue at all. Same tubing diameter.
K**M
FA15 Alkaline Water Filter Cartridge - I like it
I do like the FA15 Alkaline Water Filter Cartridge for the improvement in the taste it makes with my 5 stage APEC RO unit. My initial TDS was about 20 and was about 40 ppm after installation. My raw tap water is about 300-500 ppm TDS. To me, the RO water always tasted a little flat, I usually added a little tap water or baking soda into my glass to make it taste better. Now I find that the RO + Alkaline filter water tastes pretty darned good and the TDS is in a good range for drinking water. The price seems a little high, but compared to the cost of bottled water and the added waste/taste of plastic bottles, it is well worth it to me. Be aware that the faucet output water flow will be slightly reduced. If you enjoy good tasting water, I do recommend this filter. Edit added: Some people recommend installing a filter like this, before the storage tank. I installed mine after the tank, before the final polishing filter to faucet. If you install this after the polishing filter, before the faucet you 'may' get a slight metallic taste.
H**M
Overall working - adds about 1 pH to your water
My faithful Sears RO system doesn't have remineralization and reads pH of around 5.3 at the RO output. Installed this remineralization filter after waiting for 10 days to receive the additional 1/4" -> 3/8" elbow adapters as the Sears RO system has 3/8" output tubing. Tested TPS and pH as the following: Before remineralization filter: pH: 5.3 TPS: 11ppm After remineralization filter: pH (settled value) : 6.4 (initial pH 8.5. pH at 6.4 after flushing output for 20 seconds) TPS (settled value) : 13ppm (initial 41ppm. TPS at 13ppm after flushing) Overall: The pH was increased by around 1.1 after flushing. The overall result is passable if you're going to get a glass or two of water at a time (initial output would be high pH and then starts dropping lower, net pH is perhaps around pH 7). If you want consistently higher pH output you can perhaps install 2 remineralization filters in series. That would perhaps give you an increased pH of 2 (I have not tested this myself). Price has increased so nothing to be happy about on that.
D**T
Seems to work as advertised
Was worried this product wouldn't work as advertised but it did. I connected this filter after post carbon filter on RO system. Water is also treated pre the RO system with having a water softener with additional sediment filters and UV. Did before and after testing of the RO water. Water becomes TDS 26 from 7 and a PH of 10.01 from 7.20. No noticeable weird taste or smell. Seems to perform as expected. Had to go up a size from filter tubing to supply line to home. Don't know why they choose to have the flow be smaller tubing if you are supposed to attach this after post carbon. My post carbon is the larger size and so I have to down the size and up again.
D**G
Install on the "generation" side of a 75-100 GPM system, not in-line with the faucet, capacity issue
What you should know about this filter: 1) It works fine, definitely raises PH. 2) You need to install it in a "low flow" situation, probably before your pressure tank. 3) If you install in-line with your RO faucet, you will quickly exhaust it's capacity. I have rain water, which has an initial PH of about 5. Sitting in tanks, PH can drop more and we believe that this can exacerbate some stomach conditions. I've played with it, I'd recommend installing in on the "generation" side of a 75 GPM system, meaning the "slow stream" that produces RO water, typically before the pressure tank. If you install it in-line, this filter simply doesn't have enough media to keep up. Alternately, install 2 of these (using "T" connectors) in parallel and it might keep up on the faucet side... You can see my test results attached.
E**R
Improved taste
I installed a reverse osmosis system for my particularly hard incoming water, and although I'm confident in the cleanliness of the output, the taste of that water is a little flat. Turns out, an RO system filters out beneficial elements as well as the bad stuff, and this inline remineralizer filter restores those elements back into your water. Taste can definitely be subjective, but this filter makes my RO water crisp and tasty.
J**A
The Secret to Better-Tasting Coffee
If you're serious about coffee, you know that water quality is everything. This iSpring alkaline filter doesn’t just clean the water—it enhances it. By restoring essential minerals and balancing pH, it gives my coffee that perfect, clean taste every single time. Installation was a breeze thanks to the quick-connect system, and maintenance is simple. I can confidently say that since adding this to my RO system, my espresso shots taste smoother, and my customers have noticed the difference! Plus, iSpring’s customer service is next-level—Nicholas personally made sure my system was running perfectly. If you own a coffee shop, this is an absolute must for consistency and quality.
N**L
Llevo varios años con esta marca de filtros y no defrauda . El cartucho de filtro iSpring FA15 ha sido una gran mejora para mi sistema de filtración de agua. Se nota la diferencia en el sabor, eliminando cualquier rastro de cloro y dando un agua más fresca y limpia. La instalación es sencilla y el rendimiento es excelente. Dura bastante tiempo antes de necesitar reemplazo, lo que lo hace una opción conveniente y económica. Además, su compatibilidad con sistemas iSpring lo hace ideal para mantener una filtración de calidad. Si buscas un filtro que realmente haga la diferencia en la pureza y el sabor del agua, este es una gran elección.
L**N
I use a sediment cartridge, carbon cartridge, ro membrane and dionizer resin bed filter with this Alkaline and mineral filter and its been working great. I use the rodi system for my reef tank, but since rodi water is essentially stripped of everything bad and good things, I could not use it for drinking purposes, so I bought this filter to remineralize the water and it did. the rodi water had 0.01 tds, and after running it through the alkaline filter, it went up to 0.14 which means I have minerals again essential minerals. The Ph was already pretty good at 7.6-7.8 but after running it through the alkaline filter it went up to 8.8-9.0, and as you may or may not know alkaline water is great for you as apposed to acidic water, and since your body is made up of mostly water it makes sense, anyway iam rambling here, so to wrap up I am very happy with the results.
M**A
Muy útil
ほ**ん
2011年の震災と原発事故で放射性物質が水道水に含まれていたということがあって、 放射性物質も除去することができる逆浸透膜浄水器を自宅に導入し、その性能の高さとコスパの良さから今でも現役で活躍しています。 フィルターは毎年交換し、各種部品も都度交換をしていってDIYで楽しみながらもペットボトル水を買うこと無く使っています。 国内の通販サイトで流通・入手できるフィルタには、1〜3段目のフィルタ、4段目のROフィルターと5段目のポストカーボンフィルターが大半ですが、6段目のアルカリフィルターはあまり見かけません。 本品はその6段目のアルカリフィルターに該当するわけですが、実際の取り付けや使用感に問題はなく、フィルタ無しにくらべてまろやかさが増します。 (ちなみに1〜3段目のフィルタを通すだけでも国内メーカーの浄水器以上の性能を得ることができます) フィルタは概ね1年で交換することが目安となっています。濾過された純度の非常に高い水が通過する為、水垢や鉄さびによって黒赤に変色することがなく、ずっと使ってても大丈夫かも?と錯覚しますが総合的には交換したほうが良さそうです。装着前は必ず水道水などで10分程度水を通しておくと良いです。 TDSメーターで不純物の測定をすると、4段目のROフィルター直後は0〜2ppmですが、5段目6段目とフィルタを通し3〜6ppmになります。非常に純度の高い水を得られることができます。 ちなみに水道水が約180〜240ppm、ペットボトル水数種類試しましたがいずれも20〜50ppmとなります。当然、数値が高ければ不純物が多いことになりますが、日本の水道水の品質基準は世界でも屈指の高さでそのまま飲んでも大丈夫なほどですので、目くじら立てる必要は何らありません。 ただ、逆浸透膜浄水器および本フィルターを通した後で精製された水によって炊く御飯やコーヒーは、水道水でつくったそれとは明らかに違い、本来のおいしさを得られます。水道水でも不味くは無いですが、さらにその上を行く、といったほうが適切でしょうか。今後も継続して使っていきたいと思います。 注文をすると米国からの海外配送となり、2週間程度待たされますのでご注意を。
G**.
Perfect but little on pricey side to other options. I wanted something to add to my 6 stage RO system which comes out at zero for my reef tanks. As I now live in a very hard water area with no reservoirs the water smells and is awful up this way. Added this to the side to which I divert the water for drinking. Comes out at around TDS 82 perfect and even better with a slice of fruit.