APEC Water RO-PH90, 6-Stage Under Sink RO System, Alkaline, 90 GPD

This is my second RO-PH90 system. Simply one of the best systems on the market, in my opinion. Uses genuine Dow filmtec reverse osmosis membrane. As anyone familiar with RO knows, filmtec membranes are the gold standard and rank among the elite in rejection rates. This is not your generic RO bought in a hardware store, although some large chains carry it. Input TDS = ~225 ppm, output TDS = ~15-20ppm. Does the job. Have not tested PH yet. Water tastes great as it does with my first system. Change your pre filters once per year or at the recommended %TDS interval and expect this RO membrane to last its full schedule of 3-5 years. This is very important. Incoming water pressure must be at least 50psi in my opinion, for this system to operate as intended. At 75psi, outgoing pressure is like a dream, even with 1/4'' stock tubing. Fills glasses quickly. Consider the 3/8" output upgrade if your input pressure hovers at 50psi as it did with my first unit. RO systems thrive on incoming water pressure, this is the most important aspect of setup! Do not skip! Simple setup as usual, although this time I needed a booster pump, incoming was 40psi at best. Remember, it can fluctuate significantly during high demand/peak times. Plan a few hours for someone not so mechanically inclined. John Guest quick connect fittings are painless. Manual is very thorough, follow each step carefully and no problems should arise. If they do, customer support is USA based and very helpful. Download and read the manual available on their website before purchasing so you know what items and skill level are required. Anyone with a few tools and willful attitude will have zero problems. Easily found an Aquatec CDP6800 kit on Ebay for $108 that is perfect for this system. Came with all needed lines, pressure gauge, shutoff solenoid, pressure switch, pump and transformer. Make sure to have a sediment filter before the pump if you want it to last. Of course, APEC also offers a version pre outfitted with either permeate or booster pump although you will need your own gauge I believe. If planning on wanting 3/8" output upgrade for PH model, please go directly though APEC to purchase with it pre installed. Do not buy the output kit here on Amazon and expect it to fit the PH filter on your unit, it will not. It is for 5 stage only. You would then have to buy a 3/8" PH filter from APEC, about $40. Save yourself some time and money going directly through APEC for the upgrade route. Not much else to say, please READ the manual and you will not have to think about this system but a few times a year for TDS tests and scheduled filter changes. Good luck!

I installed the APEC Water RO-PH90 6-stage alkaline under-sink reverse osmosis system and have been very impressed with the water quality. The taste is noticeably cleaner and smoother than our tap water, with no chemical or metallic aftertaste, and the alkaline remineralization stage gives it a pleasant, “fresh” feel that’s great for drinking on its own. Knowing it’s designed to reduce up to 99% of common impurities and is NSF certified adds a level of confidence that the performance matches the taste. To take it a step further, I added a small under-sink tank heater that brings the filtered water up to near-boiling temperature. That combination has been fantastic: we now have instant hot water for tea, coffee, and cooking, all coming from the RO system rather than the regular tap. It’s extremely convenient for busy mornings or when guests are over, and it saves time compared with boiling water on the stove or waiting for an electric kettle. The RO-PH90 output is strong enough that the system keeps up well with our daily drinking, cooking, and hot-beverage needs, even with the heater drawing from it. Installation takes a bit of effort and planning under the sink, especially when integrating a hot tank, but once set up, the system is low-maintenance and reliable. Overall, if you’re looking for great-tasting, clean water and like the idea of instant hot water for tea or coffee, this RO unit combined with a small heater is a terrific upgrade for the kitchen.

I have had an RO system for 20 years (Everpure ROM) and it finally got to the point where it was cheaper to buy a new system from APEC than a complete set of filters/membrane from Everypure (Pentek). The system arrived a day early with very clear installation instructions. To be fair my installation was easier because i had the feed line and waste line already installed from my prior system but it went together easily, seems high quality and started producing filtered water right away. this system produces water faster than my old system filling up the 4 gallon tank in under 3 hours - it thrives on my house water pressure of 60 psi. i like the taste of the PH increasing filter lets see what it does to my electric kettle, ice maker and coffee maker the only installation glitch was the o-ring on one of the carbon block housings. it was leaking and even after several re-seating and application of good grade silicone it weeps a tiny bit. The o-ring was slightly too large and never fit tightly in its groove. not a bit enough issue to knock down to 4 stars. will update my review if any problems appear in the months ahead but so far it appears to be good value.

Edit: I upgraded to 5 stars because the product itself is amazing. A wild upgrade over my old GE system. Packaging concerns remain but I think you'd be hard pressed to find a better product for under sink RO. Seems good quality and love the standard size high quality USA made filters. But item arrived damaged (completely shattered fitting into the filter manifold) due to lack of protective packaging. Im going to repair myself because I don't want to wait multiple days for a replacement but for an over $300 item I expected decent packing. Modern delivery services don't care at all about fragile tags or anything else frankly. 5 star product 1 star packing.

LOVE this system! I used to buy water and have to carry around jugs of it and its so convenient now to just turn on the special tap and have fresh clean water all day every day! Shipping was super fast - next day fast - and I installed in that nite. Talk about instant gratification! INSTALLATION: The system is relatively easy to install yourself. I do have a lot of handyman type experience, however I think there is nothing overly complicated here. You have to turn off the cold water supply under the sink, unscrew the sink hose, screw in the adapter, reconnect sink hose. Then you have to connect the system together, most of which is pushing the right color tubes into the right receptacles, very easy. The most challenging part was installing the extra water spigot, you have to do some under sink gymnastics with the tiny lock nut that holds the spigot in place from below. This is my major complaint: this lock nut is tiny and very inconvenient to screw in, as compared to installing other faucets. Definitely some room for design improvement here, but once you get it on, its done and out of sight and out of mind. Suggestion: have the right size wrench in multiple configurations here, so you can find the one that fits in the tight space underneath. If you don't have a partner to hold the spigot above in place while you turn from below, tape it in place with packing tape :-) Once you install the whole system, turn on the cold water, turn on the water supply to the system, and open the tank valve, and let the tank fill all the way (2-3 hours), drain all the way to flush system (about 5 min), the refill tank (another 2-3 hours) and you're good to go! Drinkable clean water on tap! The system comes with good clear instructions and pictures, follow those. I'm just giving you a quick rundown here so you have an idea of what you're in for. OTHER CONSIDERATIONS: I bought this on Amazon. I wanted the fast shipping with my Prime account. Be aware that Amazon ships these AS IS without modifications. If you want the Quick Dispense Upgrade, I'd just order direct from Apec, as they will modify your system to Quick Dispense for you (change the 5th and 6th stage from 1/4 to 3/8 so your water dispenses faster). I ordered the RO-PH90 system and the upgrade kit from Amazon, only to realize that because I ordered the 6-stage system, I still need to buy yet ANOTHER filter, the 6th stage, at 3/8 which is another $45. If I bought direct from the company, I'd save myself the $45 plus they'd change it out for me. As it is now, I'll just use up the 6th stage filter that came with it (they last for 6-12 months) then I'll swap it out for the 3/8 faster flow filter. Not a big deal. But letting ya'll know in case it helps :-)

I will start with the good part, my family likes the taste of the water. I can’t tell the difference from bottle water and this unit but they are happy so I’m happy. Price is inline with others so no complaints there. Now for the bad part, since I purchased the unit I have replace all three filter cases for filter #1-3. Due to water leaking from the 1/4” holes on the caps and the seal failing between the cap and main body. I’m not talking about the o-ring, the actual mating surface no longer seals. Yes even with a brand new o-ring. Every time I replace the filters something kept failing. Very frustrating. I have pictures of the issues. You can see where the caps started splitting where the 1/4” fitting screw into. Keep in mind these fitting are not touched during normal filter changes. But they all have failed. Lastly I would advise you not to purchase these unit try any other brand but if you must have it, take this advise: pre purchase all filters and o-rings for filters 1-3. Purchase at least 3 10” filter housing for filters 1-3. And you should be ok. Just keep in mind that you can’t buy the housing through Amazon, you have to buy directly from manufacturer which the price per unit is fair but they will charge an arm and a leg for shipping. As of 08/20/2026 I have replaced all the 10” filter housing with different manufacturer and hoping they will improve the situation.

We are getting use to the taste. It is a large system and takes up a lot of under counter space. We had a similar system before and putting nutrients back into the water was a must this time. The faucet is beautiful and the system was super easy to install.

I have purchased and installed many APEC RO water systems as everyone who come to my house tries my water and loves it. I then show them how easy it is to install one and many do. Prior to this system I owned their 90 GPD system without the PH add back feature. I suffer from chronic acid reflux, and found research that shows that regular RO (lower PH) water can actually trigger stomach acid production, so I switched to bottled alkaline water and found that sure enough, I saw an improvement. I was bummed that I was going to have to buy bottled water, and not just have it on tap in my house so I went in search of alkaline water at home and found this. Sure enough it is great, but I do have a few notes if you are replacing an older RO system with this one. Prior to installing this system my APEC RO water was reading at an alkalinity of around 5.5 as measured using a meter purchased here on amazon. After tinstalling the new system, it is currently reading at around 9.5, which is competitive with most "alkaline" bottled water. I am so happy with this. As far as install, this system uses a 1/4 inch apec line for output to the faucet, and in all other places where the other (at least the older) 90 GPD system uses a 3/8 inch line. This worries me a bit as I may not see the same strong flow-through I had with the other system. Perhaps more importantly, it means that install is a bit tricky if you want to leverage the old lines, particularly the line to the faucet and tank. You will likely need at least on 3/8 to 1/4 inch reducer fitting, two if you plan to use the old tank. I believe the "waste" line on the old system already used 1/4 inch so you should be fine there. One other note is that the seals on the inside of the filter containers seems to pinch easily compared to the old system. Double check that they are seated properly before screwing on the container, and be careful not to over-tighten. Ultimately I am very pleased as everything comes with the quality I expect from APEC and I am very happy.

Very good quality RO filter Decent manual and instructions for installation So far so good Only had leakage from the needle valve however fixed the issue with using more teflon tape inside and wrapping outside with water leakage pipe repair tape. Now working perfectly

First time installer. Instructions made for a very easy install. Water tastes very clean. Took about a week to get used to taste of alkaline/remineralized water. I bought glass bottles to refrigerate water so now I have the best tasting water around

Es un sistema super padre, fácil de instalar aún cuando tuve que perforar granito, pero eso es otra cosa, las instrucciones son sencillas, considerar colocar muy bien el teflón en las terminaciones de metal y contar con la herramienta necesaria, el tiempo de llenado fue poco más de una hora ya que cuento con bomba de presión para todo el sistema hidráulico. Consideren tener buena presión o instalar una bomba con el sistema. No tiene sabor y no tiene acidez.

Las instrucciones de instalación, muy claras y acorde al producto. La calidad de todo lo incluido en el kit impresionante. Hasta ahora todo muy bien, pero cometí el error de no comprar el kit que viene con la bomba incluida y ha sido un poco complicado lograr la presión requerida para el correcto funcionamiento.

The beast takes a lot of room under the counter but we love it. Wouldn’t want to do without. The water is delicious and no longer smells of chlorine, is crystal clear and yet doesn’t taste “dead”. Thank goodness hubby has plumbing skills. It wasn’t that simple to install.