iSpring CU-A4 4-Stage Ultra Filtration Under Sink Water Filter System

Update: As per my review below, I had some trouble installing due to instructions that were not really clear or suited to this particular product, which Ispring says is brand new. Since then they actually tracked me down and cared about what I had to say. According to them they are rewriting the instructions, not shipping with the funny dust caps, and considering additional parts to make the installation go smoother. I was impressed because in this day and age few companies actually seem to care about what their customers really think. I have come to the conclusion that this company does. And the filter system is now working fine, so don't hesitate to buy. I'm leaving my review below in case it takes a while to update the instructions. It might shave a few hours off someones install time. Changed to 5 stars. If you have any problems they will definitely help, and that is a really good thing. ================================================================ Just finished the installation. I'm a pretty handy monkey, but the installation took about 5 hours of my time (including 3 trips to the home improvement store and a some-what helpful phone call to ispring). First-off the manual is misleading and clearly written for another product or previous version of this product (or maybe a new-fangled sausage making machine). The parts of the manual that do apply to this product, like how to connect the little push-on connectors, suffer from an excess of brevity and lack of detail and conciseness. In an attempt to be helpful to future purchasers of this product, at least until ispring updates these kits and instructions, here's what I learned: First tip: the faucet included in my box does not require a 1/2 inch hole, as the instructions state, but a one inch hole. Actually one inch is too tight, make sure you have a 1 1/8 inch hole saw attachment for your drill, and make it a good bi-metal one if you need to cut through a stainless steel sink. Home depot sells rigid brand bits that suit this purpose. It will run you about $15 unless you already have a rigid brand bit shaft (or equivalent). Second tip: the faucet that came with my filter has three colored plastic hoses already permanently attached. Red, white and blue (I dig the patriotism). Unfortunately which gets attached where is not mentioned anywhere in the manual. In the manual it says to screw the water hose to the bottom of the faucet. Clearly referring to a different type of faucet. Also if the three hoses were just a little longer you would probably not need to bother adding extension hose (an extra leak risk). More on extension hoses later. The colors are mentioned in the Amazon description, way at the bottom, but it bears repeating. "Connect the BLUE tubing of 3-color tubings on the faucet to cold water line, RED to the 1st stage on the right, WHITE to the 3rd stage on the left." Note: This is #ssbackward if you are from an English speaking country ... just saying. Third tip: The filter box itself has funny little horn or funnel shaped things on the ends of the inlet (left) and output (right) angle connectors. These are not mentioned at all in the manual. You can not push the hoses on with these in place (you can try as I did ... if you get excited by frustration) because these are some weird sort of dust plugs. You must pull up with your fingernail on the very outer ring of the connector (pushing it on a spring ever so slightly towards the more bulbous part) then with other hand pull the horn thing out. You can discard these, or I found they make nice hats for very small garden gnomes. Basically you can connect the red and white hoses now by pushing them with force into the connector until they snap. Pull back a little to make sure it is connected. If you need to cut extension hose cut it straight, and use the supplied double-sided connectors. I recommend you push the little blue horseshoe shaped clips (supplied) between that outer part of the connector and the more bulbous part. These (I think?) are to make sure the connectors can't shoot apart from water pressure. No mention in manual about these. You can leave them off, as I did at first, if the under side of your sink needs a good spraying out. Fourth tip: In order to connect the blue hose to the cold water line you need to first install some parts. My sink had a 3/8 inch stainless steel hose with female compression fitting attached to a male 3/8 compression fitting shutoff valve coming out of the wall. Pretty typical I would assume. The kit comes with a 1/2 inch plumbing style thread, male to female connector, with a hole to thread the valve the blue hose goes onto, in the middle. A way to tap into your cold water line, would be eazy peezy if it was threaded for 3/8 compression fittings, but it's half inch and has coarser plumbing style threads. So off to the Home Depot you go. Don't forget another roll of Teflon tape to add to your Teflon tape collection while you are there. Actually the folks at the Home Depot weren't that helpful (surprised?), but the small local hardware store in my old town was. You will need, as it turns out (if your sink is like mine) a 1/2 inch plumbing style male to 3/8 inch compression male adapter to connect your current hose leading to your cold faucet to this new part (btw thread the little supplied valve the kit came with into this part with a little teflon tape first so you can get it good and tight before you are lying on your back under the sink). Then on the other end you will need another short stainless hose (only way I can find to do this with available parts ... why it took three trips) 1/2 inch plumbing female, which attaches to other end of this new part, 3/8 compression female which connects to the part your faucet hose used to be connected to. These parts should run less than $15. Tip five : To connect the blue hose to the metal valve from the previous section you need to put it against the nipple, screw off the nut collar and slide it down the hose temporarily, then push it on the nipple all the way, and man it's a tight little bugger (I sprayed the nipple with a little Pam cooking spray, hey it was in the kitchen), then put that nut collar back on and tighten it down real tight with a half inch wrench. Why these filters don't come with a 3/8 inch compression fittings on each side of the filter box, so you can just screw your standard hoses on that you can get from any hardware store, is beyond me. There must be a reason. Maybe these filters are designed by the same folks who design those charming "blister packs" that you need a chainsaw to open? When I tested the water it was cloudy and tasted a little funny, it got better after I ran the tap for a while. Now it tastes pretty darn good. Even my cat likes it. Hopefully it will not develop leaks.

Very easy to install and it's an easy replacement for the tank that wore out. Once installed, water pressure is very high, and we now have a strong stream running from the faucet. Also went through the easy process to register the tank for the warranty. No issues and I was guided through the process by a representative named Robert. iSpring products are great and I highly recommend them.

Install was a bit tricky, it took two hours, mostly figuring out how to do it, not the work itself. Once we figured it out, it took hands down 15 min! We were lucky and our cold water was already separated into two since I was putting the filter in the place where I had hot water faucet. Water tastes so much better than the tap - you can really taste the difference! (Totally worth the trouble of the install! :) Arrived promptly, packaged securely in the box, but as other people claimed the instructions are a bit unclear for a not so handy monkey as me when it comes to plumbing. I think it might be too technical and sometimes vague. Since I am still somewhat handy, I could deduct from the images in the instructions that somehow one tiny tube stopper part was missing from the package. Well, what is a gall to do? I contacted the company's sell department though their website (123filter), and did receive a prompt response the next day. The whole issue of missing little fitting got promptly resolved free of charge, and even got a USPS tracking provided! Now, if that is not exceptional customer service - I don't know what is! The product itself feels sturdy; nothing feels cheap about this system. I must say that I love the faucet included! Oh! It is beautiful! Some of these faucets for these type of undersink systems are sold by other companies for 80 bucks, and it looks nowhere near what this faucet looks like! This looks like Neiman Marcus compared to Macy/ Target! The price for this system is fair - I don't think anyone is fleecing you with this product on quantity or quality, and you are not fleecing anyone either. What is a great deal are the replacement filters for a year go for about 80-90 bucks, which I think is also really good compared to other systems. I hardly use my GE fridge water filter and basically pay around that much for that filter for a year. AND if you have some issue with installation (one-time time investment) - contact iSpring - they got your back! :) I picked this filter on the day I decided that my new condo needed a undersink filtration filter. I already knew quite a lot about filters so I was not a novice in that regard. I knew what a good filtration system should filter and cost. If you are looking for a system right now, please make sure you look at good quality filters based on what is actually being filtered (filter type), original cost, and then also take into account filter replacement cost. I bought this filter system based on these criteria. Choosing a right filtration system is quite a pain, especially for under the sink products. It can takes a good month of research, comparison of products, and then finally price hunting. In the process one learns enough about water germs and contaminates to start believing that nothing short of atomically decomposing the water will purify it enough! I went though this before with another system, and didn't want to obsess about percentages of stuff that gets filtered that I did not even know existed prior to the clean water quest I now realize choosing a water filtration system really is! Brita was one of my first water filtration system that I had attached to my faucet after I had DC water authorities test my DC water in my fancy Dupont Circe apartment. I learned that my cold water had enough chlorine in it as recommend for a pool. That was ten years ago. Since I came to DC from Sweden, I must confess that I was at the time absolutely ignorant of the fact that faucet water could be harmful. So I started with Brita carbon filters, which followed other over the sink and under the sink water filters. Since then, I have solid quality filters everywhere, and I don't live in DC anymore! If you think chlorine is no big deal - try drinking pool water for three years and see how your insides feel. SIDENOTE: There are quite a few parts in the package; I do think it would be helpful if the company included pictures of all parts that should be in the package and how they fit together because most of them I wouldn't even know what to call. A youtube video as for the osmosis product did help a bit, and I think if there would be one for this product as well, since not all clean-water enthusiast are osmosis converts, that would resolve the whole installation issue completely!

"Israel, August 17, 2026 After many years, I replaced my tank with this iSpring T32M. It seems excellent. In just 7 minutes, everything was replaced and rinsing without a single drop of water on the floor. I promise to update my review either way. Amazon has never failed me, and iSpring seems great!"

I'll give this 4 stars for being what I wanted and at the best price and appearing to work (a good filter that removes VOC's and doesn't waste water or require a separate tank). I took a star off for the installation manual. Installation was tricky, mostly because I have never installed an under sink water filter before. In retrospect, there aren't that many steps and I probably could do it again in 30 minutes. As it was, it did take multiple hours with some indecision and a trip to home depot. Here are my particular installation notes, which are meant to compliment what other reviewers have said. This is not a complete guide. 1.) The instructions do suck. The wording is hard to follow and the pictures don't really illustrate what to do (and they are low res). One picture has an arrow to where a drainage tube would go, but this model doesn't do reverse osmosis and doesn't need one, but that detail causes confusion. Incidentally, the tape on the bottom of the box said "Reverse Osmosis" on it which made me questions things more. The most valuable thing in the entire book is a single picture called "water route diagram" that shows you how the main unit should look when hooked up. 2.) The cold water tap/adapter that came with the unit was 1/2 inch in size. As mentioned by others, my cold water supply is a 3/8 inch connection. However, the end of the flex pipe that connects to the faucet is 1/2 inch, so I was able to install the adapter up there without any extra parts. Sadly, I ended up going to home depot studying the various tubes and adapters before I realized this would work. 3.) There are little plastic cones going into the tube valves of the unit. Nothing mentioned them, so I watched a video for a different model to know how to proceed (I didn't want to break anything which I think I would have if I tried to yank them out). There are little blue horseshoe shaped bits of plastic holding an inner plastic piece in place. Pull those blue horseshoes off, push in the inner plastic part around the cone towards the unit, and then the cones will release. The reverse action is similar to how the tubes are installed. 4.) All my tubing connections leaked the first time because I didn't use enough force to push them in. It takes a decent amount of force to get the tubes to slide through the inner seals/washers for them to be water tight. With wet hands, I had to remove the tubes and retry several times for it not to leak. 5.) Like others said, red tube goes from the cold water valve to the filtered water faucet. The blue goes to the right side of the unit next to the stage 1 sediment filter, and the white tube exits the left side next to the stage 3 block carbon filter. I read another review that claimed the order was left to right instead of right to left. That was not true for me and the order of the 3 filter stages on my unit matched the 3 pictures of the models on the front of the manual. 6.) If your sink had a cover over 2 soap or water filter holes and you had to expose 2 holes to install this filter, hardware stores sell single sink hole covers that screw in and cover up the extra hole. I don't plan on testing my water in any way. I assume this filter does it's job. The water tastes good to me though I doubt my ability to judge that. It's still coming out mildly cloudy after 5 minutes of running it, so I'll post back if I'm unhappy with how things look later on.

I bought the iSpring T32M to increase my RO system's capacity and pressure. The initial bladder pressure was perfect at 7.5 psi. Works great and excellent water flow! Great customer service from Robert at iSpring too.

Nice and fit very well under the sink I set up iSpring CUA4-BLK 0.01 for my mom, The water test so much better than water from the refrigeration. I found leak after completed set up I was very disappointed. usually, I don't get support product after it found not helpful sometime before, but this I have to try because this good product I do not want to change it, so I call customer service, I was talking with Nick explain the issue and Nick did all his best helped fix the problem. Now my mom happy enjoy her best water from iSpring and thank again Nick for support.

First of all, I love these filters. I have the three step outside for the whole home and I have the sink ultra filtration. I love these things. It saves me a ton of time and money as well from having to go to the store to buy a new water. Total taste difference total different feel of the water from showering washing dishes, no scale no hard water. But I’m really also rewriting this review because Sean has been a great help for me. I had a little issue with the under sink filter system and he wasted no time to reach out and help me with this shout out to you because I use the system every day and it’s nice to know that there are people that are responsive to questions issues that arise. Great company I’m out in LA California so our water is all over the place so it’s nice to have the systems and have a great company that supports its customers and customer service representative like Sean.

Wer eine zuverlässige Speicherlösung für seine Umkehrosmoseanlage sucht, trifft mit dem iSpring T32M eine sehr gute Wahl. Meine Eindrücke: Ideale Kapazität: Die 12 Liter (3.2 Gallonen) Bruttovolumen sind absolut ausreichend für den täglichen Bedarf. In der Praxis reicht das gut für einen 2-Personen-Haushalt aus, um immer genügend gefiltertes Wasser parat zu haben. Qualität: Der Tank ist top verarbeitet. Die Materialien wirken hochwertig und die Tatsache, dass er lebensmittelecht ist, gibt ein sicheres Gefühl bei der Trinkwasserlagerung. Anschluss: Der standardmäßige 1/4"-Anschluss macht die Integration in bestehende Systeme kinderleicht und hält absolut dicht. Fazit: Ein grundsolider Wassertank, der genau das hält, was er verspricht. Für Paare oder kleine WGs die perfekte Ergänzung zur Osmoseanlage. Klare Empfehlung!

My Experience with the iSpring CU-A4 Under Sink Water Filter I recently installed the iSpring CU-A4 under sink water filter, and I'm genuinely impressed. As someone who's always been a bit skeptical about the true efficacy of home water filtration systems, this unit has completely changed my perspective. First off, the installation was surprisingly straightforward. I'm no plumbing expert, but the clear instructions and well-organized components made the process relatively painless. Within an hour or so, I had fresh, filtered water flowing from my dedicated faucet. And what a difference it makes! The most noticeable improvement is in the taste and smell of the water. Our tap water, while generally safe, often had a slight chlorine odor and a somewhat metallic aftertaste. With the iSpring CU-A4, that's completely gone. The water is crisp, clean, and incredibly refreshing. It's truly a pleasure to drink, and I find myself reaching for water more often throughout the day. Even my coffee and tea taste noticeably better. I also appreciate the compact design of the unit. It fits neatly under my sink without taking up an excessive amount of valuable cabinet space, which is a huge plus in smaller kitchens. The dedicated faucet is sleek and unobtrusive, blending well with my existing fixtures. While I can't scientifically measure the contaminant reduction, the peace of mind knowing that my family is drinking water filtered through a reputable system is invaluable. The four-stage filtration process, including activated carbon and ultrafiltration, gives me confidence that we're significantly reducing chlorine, sediment, and other common impurities. In conclusion, the iSpring CU-A4 under sink water filter is an excellent investment for anyone looking to improve the quality of their drinking water. It's easy to install, produces great-tasting water, and offers genuine peace of mind. Highly recommended!

I waited a while to write this review as I wanted to see how this held up for a month. I can say this has worked perfectly, looks classy (not cheap), and the water has since a nice clean taste. I should have put this in years ago however I was always concerned that it would be too hard to do, or would leak or just from not knowing enough how these work. The install was literally under 20 minutes, so straight forward and the components, hoses etc are high quality. The hardest part was drilling a hole in the stainless steel sink, however I did not care much as the sink is old and we are renovating the kitchen fairly soon. Connecting the hoses was literally a snap, the unit fits under the sink no problem, and I made sure to leave the hoses longer so I can pull the unit out easily to change the filters. The faucet itself looks high end and the lever has a nice weighted feel to it, not cheap moving, more of a smooth range of motion. The only thing I wish was a little more solid was when I turn the faucet from side to side, say filling up the dog bowl on the counter, it is kind of flimsy, I wish this had the same feel as the water lever did. When I hooked everything up I had to let it run for a good 30 minutes to clear the filter sediment out, and for the first couple days when first used in the morning, there would be some sandy sediment. That was gone by the third day and crystal clear since then. I want to get the water tested and compare to this to see what is really filtered, that is my only question, you are taking the companies name that the filters work, and this is why you need to review and do some research. So far very happy and would buy again no problem!

Super easy installation! Very tasty water! Took away the tap water smell, and it does make a big difference although Amsterdam has one of the best tap water in the world! Quality product

I use this product to filter water for our production process as well as for drinking. I did need some hoses the larger tank did not come with so I called up Richard and he was able to help me out with some complementary hoses. I was up and running within a week!!