Waterdrop K19-S Countertop Reverse Osmosis System, 4 Stage Reverse Osmosis Water Filter Countertop, 3:1 Pure to Drain, Reduce PFAS, No Installation Required, BPA Free

I've had this for nearly a year. I wanted to wait this long because you never know how long an electric pump might last. The machine is still going strong. Water taste is good. I can definitely tell its removing hard water, chlorine, etc. even better than good fridge filters. I chose this because standard RO systems that hook up to your sink usually have large 5 gallon tank. With the plumbing the way it is under my sink the tank doesn't fit.PROS1. The unit has UV light for killing viruses. This is actually something you don't get with traditional setup.2. The taste is pretty good. I usually drink water from fridge which has good filters. I use the RO water for tea and coffee where hard water stains would buildup.3. The digital TDS reading is another nice-to-have.4. The rubber feet are amazing if you need something that doesn't slide around. I put it on sliding pad so I can easily turn it around to refill the tank. That allows me to tuck it way back under cabinets.5. Easy setup. Insert filter, plug it in, fill water tank.CONS1. Sometimes it doesn't fill the correct number of ounces. It's rare. I'm talking about after flushing routines and when the internal reservoir had time to fill.Suggestions for improvement1. The common 4, 8, 16, 32 oz options are mostly good enough. My morning routine is 24 oz coffee though. I have to use the 8 oz then cycle to the 16 oz after to get the amount I want. Minor inconvenience but it can definitely can be improved with a numpad so I can select exact desired amount.2. I'd like to see a front removable water tank so I don't have to spin it around to fill.

I have to make a disclaimer. I just bought this. However, I like writing reviews in stages, and I will be back to update this in the future.I use a different Waterdrop under sink filter system to filter my drinking water. I tested my water, and it is safe coming from that filter (no concerns there). My water comes from a limestone aquifer, and it has a lot of limescale. My water has a TDS of about 320. Most of the TDS readings are calcium and magnesium, and my water is insanely hard. My undersink filter removes all the stuff that is in my water that is truly harmful, but it does not remove the stuff that causes things to calcify my appliances. The stuff that causes my TDS also makes my water taste good. Why did I buy this then? I bought this for my coffee maker. My coffee maker always gets gummed up with calcium in a short order.Personally, I think RO systems are overkill for most cases. RO systems do have their place removing certain types or excessive quantities of contaminants, and the systems definitely have a place. Most people mistakenly believe that low TDS is safe water. I can assure you that is not true. If you do not believe me, take some distilled water and pour some acetone in it. The water will will have 0 TDS, but it will be unsafe to drink.This has been a good system so far. When I start out on a tank of water, I get TDS readings of about 20 ppm. As the system recycles water during use, it will climb to about 40 ppm. I tried the water directly from the filter. I am not a fan of drinking it straight. It is not because the machine is adding a funny taste, but I think RO water tastes flat. The only con I have with this machine is the fact that I have run the tank dry filling up my coffee pot. The pump will kick on, but the unit will not continue dispensing the selected amount after the tank fills. That is a small gripe.For those who want to know, this RO unit removes flouride. I do not believe the government should be force medicating people without their consent (adding flouride). Every filter I have can eliminate that from my water.Edit: I have used my system for about a year. I have not had any issues with it.

Where do I start with this thing...... It got one star because the water it produces actually tastes great. But the design is flawed and the manual is almost useless, as it doesn't explain how this thing works. In general it takes around 1 hour of messing around with this thing to get about 5 litres of purified water from it. To get that 5 litres of purified water, it uses up 3 times more water !! So the claim that you get a 2:1 purified to waste water ratio is miles off. It's more like a 1:3 ratio of purified to waste water.It also has a really bizarre design fault. If you fill a 32Fl oz bottle (maximum fill setting on the machine)The unit then pumps out so much waste water, that it overflows into the tap water feed tank, and causes the purified water to increase on the TDR meter. This overflow can also can cause the water to have an unpleasant taste.The manual is totally useless in trying to understand the machine's operation and how to fill the rear plastic tap water resevoir. On the back of the tank is a scale in Fl Oz. The read plastic tank is divided into two tanks. The larger one (160fl oz capacity) is the Tap Water Supply tank, which you fill with tap water. The second smaller tank is the Waste water tank. The instruction manual doesn't tell you how to fill this, so when I first got it, I filled the tank to "MAX" Which is totally incorrect, as this will also fill the waste water tank, and the purified water ends up tasting awful.The correct way to fill the tap water tank is to fill it to around 110fl oz so that the tap water doesn't overflow into the waste water tank. When the machine outputs purified water, the tap water tank level goes down and the waste water level goes up. In this way the water in each tank stays separate. Unfortunately as I mentioned above, as you empty the tap water tank, the waste water tank fills to the point where it overflows into the tap water tank and the machines allows this to happen.I need to get about 7 - 8 litres a day out of this, and so I spend over an hour and a half trying to do that. It's pathetic. We ended up purchasing a tankless undersink system, which produces water at a much faster rate.This RO countertop machine is best avoided unless you have a few hours spare every day to refill the tank in order to get a decent amount of water out of it. It's basically a toy, not a useful kitchen appliance. But yes, the water it produces when used properly tastes just like high quality bottled water.