How to Install a Reverse Osmosis Pressure Tank Step by Step

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Whether you’re replacing an old tank or installing one for the first time, installing a reverse osmosis storage tank is an important part of setting up your RO system.

There’s more to installing the tank than simply hooking up the tubing connections and letting it rip, so you’ll want to complete the process properly and avoid any problems down the line.

Let’s take a look at the installation process in step-by-step detail – so you can get your storage tank installed in no time.

Key Takeaways

Installing a reverse osmosis storage tank is an important part of installing any RO system. The process is straightforward, and even if you’re a DIY novice, you’ll be able to complete in less than an hour. Here’s how:

  1. Choose an installation location close to your RO system which offers enough space.
  2. Remove the RO tank from its packaging.
  3. Wrap Teflon tape around the threaded tank outlet at the top before screwing on the tank valve.
  4. Connect the tubing.

How to Install a Reverse Osmosis Pressure Tank

Before you begin the installation process, you’ll need to plan out the installation location and make sure you have the right tools on hand…

Location: Where to Install an RO Pressure Tank

A typical 4-gallon storage tank measures about 12” wide x 15” high, so you’ll need at least this much free space to fit the tank. Add an inch or so to the height to give you space to install the tank valve on top.

You generally want to install the tank under the sink as close to the RO system as possible. While you can install it in a nearby cabinet if necessary if the distance is longer than 10 feet you’ll run into issues with losing water pressure.

Preparation: Tools and Supplies You’ll Need

  • Teflon tape
  • Tubing cutters or exacto knife
  • Storage tank
  • Tank shut-off valve
  • Tubing

plumber installing reverse osmosis system under sink

Step 1: Preparing the Tank

First, remove the tank from its packaging.

Use Teflon tape to wrap several layers around the outlet on top of the tank. Wrap it in a clockwise direction so that it tightens when you install the tank shut off valve. This tape will ensure a tight fit and reduce the chances of leaks.

Next, position the shut off valve on the tank and hand tighten it until it feels secure (be careful not to overtighten).

Step 2: Positioning the Tank

When it comes to positioning your RO tank, there are a few things to consider.

  • First of all, you’ll want to position it where it can easily be accessed and removed should you need to sanitize or replace it.
  • Another thing to keep in mind is that storage tanks can be positioned either on their side or standing up. This gives you a bit more leeway when it comes to installing it in tight spaces.
  • As mentioned previously, don’t install it in further than 10 feet away whenever possible. Otherwise, this will lead to low-pressure issues.

Step 3: Connecting the Tubing

Next, connect the tubing running from your RO membrane outlet to the tank valve. For a quick-connect fitting, all you need to do is push the tubing into the fitting until you feel a ‘snap’.

If your existing tubing is too long, or you don’t have tubing running from your RO membrane, then take a section of tubing and cut it down to length with tubing cutters or a sharp exacto knife.

Now all that’s left to do is turn the tank shut off valve to the open position, turn on the feed water valve of your reverse osmosis system, and wait for the tank to fill up with filtered water.

How to Replace an Old RO Storage Tank

If you’re replacing an old RO storage tank rather than installing a new one, then there are a few extra steps to be aware of:

You’ll want to start by shutting off the cold-water supply under the sink and then opening the RO faucet to let out any remaining water in the system.

Now, disconnect the tubing connection attached to the shut off valve on top of the old tank. For quick-connect fittings, depress the collar of the fitting with your fingertips and pull the plastic hose loose.

If you want to re-use the old tank shut-off valve, then remove it by turning it counter-clockwise until it comes free. It should come loose without the need for any tools. Remove any leftover Teflon tape from inside the valve’s threads and you’ll be good to go.

Now you can install the new RO storage tank following the process described further above.

DIY vs Hiring a Pro

Installing an RO storage tank is a pretty straightforward process that you should be able to complete in just 15 minutes or so. Even if your DIY skills are not up to par, the job can be done easily and requires almost no tools.

Of course, if you feel the job is beyond your skill level, you can always hire a plumber or general contractor to complete the job for you. This will add a significant cost though, as a plumber will generally charge a service fee or minimum charge for jobs that take less than an hour. So you are probably looking at somewhere between $75 and $150 for a simple tank installation.

If you have any questions about RO pressure tank installation please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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