Buying and Installing a Reverse Osmosis Filter System

If you’re like me, you are concerned with having access to water for your family for drinking and cooking and food preparation and maybe even your fish aquarium that is as pure as possible without necessarily breaking the bank. It costs quite a bit to buy filtered bottled water from the store, especially in single serve bottles. It is also not very environmentally friendly either with all the plastic bottle waste. Obviously, the bigger the containers, and the more you buy, the cheaper it is. But you can’t keep huge amounts of water just sitting around in containers. It takes up a ton of space. It is heavy to lug around. And, if you don’t consume it in a high enough volume, it is bound to sit on the shelf for longer periods of time in bottles that are possibly not the best containers for an extended amount of time.

For drinking water, we have a filter system included in our refrigerator that is actually not that bad. It is certified to the NSF 53 standard for removal of chlorine and organic and inorganic volatile compounds. This has provided us somewhat clean, healthy, cold water for some time. The problem here, though, is that we have fairly hard water that includes quite a bit of dissolved lime and calcium. These minerals combine with the chlorine used to treat the water. So, even though my fridge filter is designed to remove chlorine, it is really only removing the free chlorine and not the chlorine that has combined with the high mineral content in our water. Additionally, there are several other contaminants that are occasionally present in our water system that are minimally right at or just below the maximum EPA guidelines. This reminds me of the old joke about the FDA’s regulations on the maximum amount of rat feces that is permitted to be found in food. Regardless of what the FDA or EPA tells me is okay, my threshold is ZERO.

Research & Decision

I finally decided that we consume enough water, our fridge is pretty slow to dispense, and the resulting water is just as hard and full of those minerals with combined chlorine. I also have a fish aquarium and have been wanting to use RO water to improve the overall health of the tank and the fish, as well. So, I started doing reading on water filtration for the house. At first, I was looking at a high capacity whole house filtration systems. That can get quite costly very quickly in the short-term. Since we are in Texas, we have no basement and are on a slab foundation. Our water main entry is buried right under the front beds of our house. So, for us, the biggest cost, by far, was the labor to trench pipe around the front of our house and under our driveway from the water main entry to the side of our house where we would need to place the system, as well as install an outdoor enclosure. Alternatively we could bring it through the wall and place it in our 3rd garage. The downside was that during the warmer months our water would be fairly warm from sitting in the filtration tank exposed to the air. We were looking at around $4,000-$5,000 in cost up front. I just couldn’t justify that expense.

So, I began looking at alternative options like an under counter Reverse Osmosis (RO) system. I did a fair amount of research and put together a comparison spreadsheet, so I could get an idea for the capabilities, quality, price of the various products out on the market, as well as the ongoing media replacement costs. One day I was shopping at Costco with my family and I came across an RO system from Watts Water Technologies, called the Premier RO-Pure Plus, that they were selling for ~$190. I read the label specs which were equivalent to many other products I had seen for easily $100-$200 more and I verified it was NSF 58 and WQA certified. I knew the price was very competitive, but I wanted to go read more about it before jumping in and committing. After reading many positive and negative customer reviews on this product, I decided it was worth taking the chance on it. I had also read that adding a Permeate Pump to the system would decrease the amount of wasted brine water from as much as 10 gallons wasted for each filtered gallon down to 2-3 gallons of waste, as well as increase the life of the RO membrane, maintain a strong tap pressure, and potentially even improve the TDS level reduction. So, I went online and I also purchased the Aquatec ERP-500 Permeate hydraulic pump for ~$64 including shipping and an install kit to pair with the system which supports the 50 Gallons Per Day rating of this system.

Installation

I finally got around to installing the RO system last night. I purchased a number of additional components at the hardware store to improve the brine drain setup, as the included drain saddle requiring drilling a hole into the drain pipe is not the most ideal option over time. I also changed my dishwasher drain configuration under our kitchen sink at the same time. This took a bit of time and planning on my part to do it right. I am pretty technical and handy when it comes to odd projects like this. However, I’m definitely not a plumber. So, it was a bit of a learning experience for me to get it right.

Here is a link to the schematic that I drew up for my installation reference, since I was not exactly following the instructions in the provided manual.

I installed the Adapt-a-valve on the cold water inlet for my kitchen faucet and reconfigured my dishwasher drain the night before. I spent about an hour total on that job. The majority of that time I spent figuring out how to secure my dishwasher drain high enough under the sink to maintain the anti-siphon configuration. Installing the Adapt-a-valve was super easy and didn’t take more than 10 minutes total. The rest of the install took me about 3 and a half hours from start to finish when I started the tank flushing process. I spent some time figuring out where I wanted the 3 Gallon storage tank to sit under the sink and where to hang the RO system itself to simplify the installation and make it easy to maintain and replace filters in the future. I wanted to put the storage tank in the space behind my garbage disposal but, it was just slightly too large to fit without removing the entire disposal. That would have also made it a pain if I ever needed to do maintenance back there, as there would have been very little space to work with. Once I made that decision, things went fairly quickly.

The install went nearly identical to the instructions. Make sure you read all of the steps completely for a particular task so you are familiar with it and do not miss any of the pre-requisites. When or if you cut any of the 1/4″ pipe, use a sharp utility knife and make sure you cut all ends as perfectly perpendicular to the pipe as possible. This provides the best seal when you insert the end into any of the quick connect fittings. Make sure you push the pipes all the way into the back of the quick connect fittings to achieve the best seal to avoid any leaks.

Hydraulic Permeate Pump

In my case, because I was installing the Permeate brine pump, it slightly complicated this particular setup. The recommended installations show the Permeate pump installed on the Permeate side between the RO membrane filter and the 4th stage VOC carbon filter (Silver). With the Watts Premier RO-Pure Plus product, the connection between the RO membrane and the VOC filter is internal and not accessible. There is a separate port on the back of the RO unit for the Storage Tank connection and the Faucet output. So you have no access to tap into that line before the VOC filter. So, I compromised and I decided to plug the included Tank outlet port with a small piece of 1/4″ tube and a quick connect end cap. I connected the Faucet output port directly to the Permeate In port on the Permeate pump. I then connected the Permeate Out port to a Tee fitting and attached the storage tank to the Tee and then connected the Tee to the faucet. This allows the Permeate pump to do its job whether the tank is filling or the faucet is on or both. The slight downside is that the water passes through the VOC carbon filter before it goes to the storage tank. That means there is no filtration between the storage tank and the faucet when you open the tap to dispense.

Custom Design Options

I installed my storage tank with a bit of additional length of 1/4″ pipe. This allows me to pick the tank up and move it if I have to and even pull it out from under the sink and place it on the floor without having to shut off the water or de-pressurize the system. I purchased a Watts 1/4″ OD Tee quick connect fitting to attach the storage tank to the line between the Permeate pump and the faucet. I also installed a 3/4″ branch drain pipe molded to a 1 1/2″ compression fit drain pipe to my sink drain so that I could connect both my dishwasher drain and the RO system’s brine drain and provide the ability to muffle the noise of the draining water.

The tricky part for me was finding all of the right parts to get everything to fit. No single hardware store had what I needed. I felt like I was on a bit of a wild goose chase. To be fair, Lowe’s ended up having the best selection and availability of the components I needed and I could get flexible drain hose by the foot in the size I needed. I need to remember that lesson to avoid wasting time again in the future with their competitor.

To connect the 3/8″ black brine drain pipe from the faucet to the drain I used a Watts 3/8″ OD to 1/2″ MIP quick connector. MIP is male threaded. I threaded that onto a 1/2″ FIP female coupler and connected a 1/2″ MIP to 3/4″ barb connector. I then used a hose clamp to attach a small piece of 3/4″ ID vinyl drain pipe to the barb connector and attached that to a 3/4″ Barb Tee fitting with another hose clamp. I wasted a lot of time at the hardware store searching for a Tee fitting I could use to connect the branch drain to the dishwasher drain and the brine drain from the faucet. I ended walking down an adjacent aisle at Lowe’s to the aisle with the tubing and components and I found they had a Schedule 80 PVC 3/4″ Barb Tee fitting that worked perfectly and was only 70 cents.

When I was installing the pH Balance Filter, I realized that it would add minerals to all of the water out of the tap. This is fine for typical use but I also wanted to have the ability to bypass the mineral cartridge on-demand when I wanted to fill pure RO water into my storage containers for my fish tank. If you look at my schematic drawing I created, I’ve shown how I used two Watts 1/4″ inline valves and two 1/4″ tee connectors to provide me that option. I only bypass the mineral cartridge when I am filling my fish water storage containers about once a week but it has been very convenient to have that capability and still be able to have mineral water out of the tap, otherwise.

System Start-Up

Once I was finished and I had double-checked all the fittings and connections, I turned the system on by rotating the valve knob on the Adapt-a-valve. I immediately heard the rush of water and could hear the system pressurizing. I watched closely for leaks and there was nothing obvious. So far, so good. I opened the faucet as mentioned in the manual startup instructions. After a couple of minutes, a trickle of water started to come out along with a couple little bursts of air and water. I then shut the tap off and let the system fill the tank. It took about an hour and a half until it went silent. I kept watching to make sure nothing was leaking. I noticed a very slight drip on the Red Pre-Sediment filter module. It wasn’t constant but every time the shutoff valve would trip and then start-up I would see a little drip collect. I reached in and fiddled with the filter canisters and noticed that they could each rotate a bit clockwise to the right, when looking up from the bottom. When I rotated each filter, it felt like they tightened and butted up against a notch of some sort. From this point on, I did not notice the drip on the Red filter canister.

Testing & Validation

In order to confirm the RO system is working and be able to monitor its filtration ability over time, I got a digital Total Dissolved Solids (TDS) tester. It is basically a probe with a digital thermometer and 2 electrodes that test conductivity of the water. It is quite accurate to within +/-2% and can test from 0 all the way up to 9,999 parts per million (ppm). I tested my tap water and it registered at 416ppm. I tested my fridge filter and it tested at 350ppm.After the first tank fill, I tested the RO water output and it registered at 36ppm. Not bad at all while the system is still priming. I flushed the tank and it filled a second time. I tested this output and it registered at 26ppm. I flushed it and filled it a 3rd time and the last output tested at 19ppm. That is pretty darn good results so far. I expect this number will probably improve another 5-10 ppm over the next couple of months, as well. By testing the water’s TDS monthly, I will be able to detect when it is actually necessary to replace the filter cartridges as opposed to just blindly doing it every 6 months. I will also be able to more accurately identify when the RO membrane needs replacement, rather than guessing between 2-5 years. The added bonus is that I can use this tester for my pool water and for my fish aquarium. So, it will come in fairly handy for me.

For reference, I did some tests to baseline the properties of our local municipal water supply and compared it to the permeate water supply coming out of the RO faucet. I used my Taylor water test kit I use for our pool to test the pH, Chlorine, Alkalinity, and Calcium Hardness. I used my HM Digital TDS-4TM TDS tester to test the total dissolved solids. Following are the results:

Municipal Water Baseline
Date	pH	Chlorine (ppm)	Alkalinity (ppm)	Calcium Hardness CaCO3 (ppm)	Grains/Gal Hardness	TDS ppm
8/3/2014	8.20	0.5	65	110	6.43	374

 

RO Permeate
Date	pH	Chlorine (ppm)	Alkalinity (ppm)	Calcium Hardness CaCO3 (ppm)	Grains/Gal Hardness	TDS ppm
8/3/2014	7.3	0.00	5	5	0.29	17

 

The RO Total Dissolved Solids rejection rate % (filter efficiency) comes out nominally to ~95.45%. With a +/-2% accuracy that gives a range of 95.23 to 95.63%.

Re-Mineralization

While RO water is quite pure for drinking water, it definitely has a different taste than typical tap water. This is due to all the normal minerals, that are healthy for you and give the water taste, being removed. In order to balance the pH a little higher into the Basic range and provide a little better taste for drinking, it is a good idea to install a post filter cartridge that adds minerals back to the water. It kind of seems pointless at first to remove the majority of the mineral content to only add it back in, after the fact. However most municipal water supplies treat the water supply with free chlorine to keep the system clean from pathogens etc. Some of this free chlorine, over time, combines with the dissolved minerals. Simply filtering the chlorine from the water does not get rid of all the bad chlorine. Additionally, many water supplies are really high in mineral content and hardness which is not necessarily good for us either. So, the RO system strips out the majority of the mineral content. It is a good idea, if you are using the RO water for drinking, to add some mineral content back in.

Watts has a pH Balance Ceramic Filter cartridge that can be placed in-line after the RO filter. You can choose to order it with 1/4″ or 1/2″ quick connect adapters and it comes in a 9″ or 11″ size cartridge. It appears that the larger cartridge simply provides a longer service life of 6 months or 1000 gallons versus 4 months.

*Installation Pictures to come

 

References

• Watts Premier RO-Pure Plus 50GPD Reverse Osmosis Filter ~$189.99 at Costco
• Aquatec ERP-500 50GPD Permeate Pump ~$54.88 plus shipping + $4.25 install kit
• Watts Premier RO-Pure Plus Annual Filter Replacement Kit ~$68 plus shipping
• Watts Premier RO-Pure Plus RO Membrane Replacement ~$50.25 plus shipping
• Watts Premier pH Balance Ceramic Filter Cartridge ~$34.75 plus 2.5″ Mounting clip at ~$0.91 and shipping
• HM Digital TDS-4TM – Digital TDS meter ~$22.20
• TDS 342ppm NaCl calibration solution – Solution to re-calibrate Digital TDS tester
• My RO Schematic