What Size Reverse Osmosis System Do I Need? And Why!

You know that having a reverse osmosis system will provide better quality drinking water for you and your family. But there are so many sizes and combinations of reverse osmosis drinking water systems available, how do you know what size reverse osmosis system you need for your family?

Size a reverse osmosis drinking water system based on 2 gallons of reverse osmosis water per day per adult male, 1.5 gallons per adult female, 2 gallons per teenager, and 1 gallon per child. A 50 gallon per day RO system for a family of up to 4 and a 75 gallon per day system for a family of up to 7.

What you need to be removed from your water and how much reverse osmosis water that you expect to use will determine what size reverse osmosis system that you need.

Let’s go over a few questions to help you decide which reverse osmosis system stages are right for you.

Why a small-sized reverse osmosis system might be right for you.

When you are looking to purchase a reverse osmosis drinking water system for your family, it is important to know that all reverse osmosis systems are not the same. There are several stages and combinations of stages for use in different situations.

If your water tastes relatively crisp and clean but you just want to make it a little healthier, an inexpensive reverse osmosis system may be perfect for you.

If you have a well as your source of water, a very simple reverse osmosis system consisting of a sediment pre-filter, a reverse osmosis membrane, and a carbon post-filter should give you high purity water at a very reasonable price.

For most well water a 3-4 stage reverse osmosis system will work fine. A 5 stage reverse osmosis system with a carbon pre-filter is best for municipal water, and a 7 stage system with UV protection is best for water that may contain harmful organic material.

You may need additional stages for removal of chlorine, poor taste, odor, UV purification, re-mineralization, or other impurities.

Why you may want a larger-sized reverse osmosis system with a little more.

If you experience re-occurring odors or unpleasant tastes in your water, there may be more than just a little bit of filtering required to get your water tasting great.

Sometimes reverse osmosis can make water taste too pure.

Some people have relatively good water, to begin with, but just want to make sure that it is as free of unwanted contaminants as it can be.

The problem with making water very pure is that it will not have any taste to it. See my article on “What Does RO Water Tastes Like.”

This lack of flavor does not only affect how much you will enjoy your water, but it will also affect how much you enjoy the taste of everything that you add your reverse osmosis water too.

Drinks like your morning coffee or tea may not have that same smooth texture that they used to. And drink mixes like ice tea or fruity drinks may seem flat and boring.

This is because the minerals that used to be in your drinking water that gave it a little flavor have now been removed by reverse osmosis.

Can you add minerals back into your small-sized reverse osmosis system?

If you really love your morning cup of coffee or tea, and you don’t want to be without that rich taste that you have become accustomed to, a reverse osmosis system with a remineralization cartridge may be just what you are looking for.

A remineralization cartridge contains minerals that are beneficial to your health to replace the unwanted minerals that the reverse osmosis system has removed.

Calcium in the cartridge is dissolved into the water, adding a milky and smooth flavor to it.

Can a small-sized reverse osmosis system remove odors from my water?

Odors and bad tasting contaminants in your water can be removed using carbon filters. Many reverse osmosis drinking water systems come with carbon filters either as a pre-filter or as a post-filter.

Having a carbon pre-filter is very important for municipal water supplies since they are often treated with chlorine to make the water safe for consumption.

A carbon pre-filter will remove the chlorine from the water before it reaches the systems’ membrane.

This is very important as chlorine will damage a reverse osmosis membrane, making it less effective at filtering out dissolved solids from your water.

Some reverse osmosis systems will have two different types of carbon pre-filters to accomplish two types of filtering.

This is mostly beneficial for the municipal water system that may have some sediment in the water.

In this case, a sediment or carbon embedded sediment pre-filter and an activated carbon pre-filter would both be used before the water goes through the membrane of the system.

What size reverse osmosis system do I need a carbon pre-filter?

There are typically two types of carbon filters used for a reverse osmosis system.

In most cases, only one carbon filter for removing chlorine from a municipal water source is necessary, but if you are concerned about other contaminants, a second may be beneficial.

A GAC (Granular Activated Carbon) carbon filter is often used when the water supplying the reverse osmosis system has been chlorinated by a municipal water supplier in order to disinfect the water from any harmful organic contaminants.

The Granular Activated Carbon traps the chlorine in its pores, preventing it from getting to the fragile reverse osmosis membrane which can be damaged by exposure to chlorine or other corrosive chemicals.

This Granular Activated Carbon is also good for removing larger sized particles which can cause the water to have unpleasant odor or taste.

If you suspect that you have finer contaminants in your water that contribute to odd tastes or odors in your water, a finer, 5-micron carbon block filter may be in order.

This denser carbon filter will remove smaller contaminants that a standard Granular Activated Carbon filter will not, and help to protect the reverse osmosis membrane, increasing the efficiency of the membrane and extending its life expectancy.

Although not all situations call for having both of these carbon filters on your reverse osmosis system, many systems come with both filters to produce better quality water.

Are ultraviolet lights on large-sized reverse osmosis systems important?

Ultraviolet light is used to purify the water of organic material that may be found in it. The water passes by the ultraviolet light and is sanitized of harmful organics in the water.

If your water comes from a well or another water source that is not already disinfected by the use of chlorine or other disinfectants, an ultraviolet light on your reverse osmosis system is highly recommended.

Because safe drinking water is so important for you and your family, having an ultraviolet light on your reverse osmosis system is a great addition to the water treatment in your home.

A reverse osmosis drinking water system with an ultraviolet sanitizing stage is not as expensive as you may think and the bulb is very easy to replace when it comes time to change the reverse osmosis filters on your system.

I have found a very reasonably priced 7 stage reverse osmosis system with ultraviolet protection that you can check out from my Recommended Reverse Osmosis Systems.

Do I need to get a separate faucet for a small-sized reverse osmosis system?

Most reverse osmosis drinking water systems have a water faucet included with them, but it is often a very simple looking one.

If you have a specific style or color in mind to match your home’s decor, there are many deluxe reverse osmosis drinking water faucets available.

You can get many contemporary styles in colors like White, Biscuit, Black, Polished Chrome, Bright Nickel, Satin Nickel, Brushed Stainless, Polished Brass, Antique Bronze, Venetian Bronze, Valueline Satin Nickel, and Matte Black.

Upgrading to a deluxe faucet is very easy, and you can always use the original faucet for a second location in the future.

Many people don’t consider how their new reverse osmosis faucet will look in their home. Even though most will look very nice in any home, if you would choose to upgrade to a nicer one, they are very easy to change.

If you have a certain color or style of reverse osmosis faucet that you want for your kitchen, check out my top choices for Reverse Osmosis Faucets.

What size reverse osmosis systems have an air gap?

One reverse osmosis system says that it comes with a standard faucet included, the next one says that is has a faucet with tube already attached, and yet a third say air-gap faucet included.

What’s the difference, and why would you want an air gap faucet for your reverse osmosis system.

Let’s talk about air gaps!

What does an air gap do?

An air gap for a reverse osmosis system is just what it sounds like it is.

It is a gap where the water that the system discharges to drain goes through a gap where the waterfalls freely through the air and into another piece of tubing.

This gap in the line is to prevent the potential water contamination in the reverse osmosis system due to the drainage of the home getting backed-up and entering the reverse osmosis system through its drain line connection.

Although this is very rare in most modern homes, homes that use a private or shared septic system may incur occasional backing up of wastewater that could contaminate a reverse osmosis drinking water system.

This is a common example of when an air gap reverse osmosis faucet would be used to protect against contamination.

Although the function of an air gap reverse osmosis faucet is beneficial in these circumstances, they do have a reputation of leaking or the drain water missing it’s intended receiving downspout.

I have come across many air-gap faucets that were unnecessary for the home and I only recommend that they are used in older homes with septic systems.

Do I need a water mineralization stage?

Having a mineralization stage on a reverse osmosis system is purely a matter of personal preference.

Some people want to add some flavor to their reverse osmosis water, and others want water with as little taste as possible.

Some people are concerned the reverse osmosis makes their water too pure and is concerned that the water will dissolve minerals from their bodies and therefore want a mineralization stage to prevent this from happening.

Although highly pure water will attempt to absorb minerals from the human body when consumed, the water would have to be very pure, and most reverse osmosis water is not pure enough for this to happen.

A reverse osmosis system will typically remove “up-to” 98 percent of the dissolved solids (minerals) that are in the water of your home.

In other words, if your home’s water has 100 total dissolved solids (TDS) in it, the purest it will likely be after reverse osmosis is 2 total dissolved solids.

Do all-size reverse osmosis systems remove all impurities from your water?

In reality, the final product water from a reverse osmosis system with 100 total dissolved solids in it would be more like 5-6, which would not be considered to be pure enough for it to dissolve any substantial or harmful amount of minerals from your body.

Having a TDS of only 100 is usually not cause for concern, and most people with a TDS in this area have no need for a reverse osmosis system at all.

But if your TDS is in the area of 100, and you do wish to get a reverse osmosis system, a mineralization stage may be beneficial.

What about having a mineralization stage to improve the taste of your water?

Most of the time, purchasing a reverse osmosis system is because you want to reduce the number of dissolved solids in your water because of poor tasting water.

This is a situation where a mineralization stage may be nice, but not necessary.

A mineralization stage on a reverse osmosis system is usually a cartridge that contains calcite (calcium) which will add calcium back into the water after it has been purified by the reverse osmosis membrane.

This will add a smooth milky type of flavor to the water which is often enjoyed by coffee, tea or drink mix drinkers.

If you are in the market to get a reverse osmosis drinking water system because your water has an unpleasant taste, but you don’t want water that is dull or flat-tasting, a mineralization stage may be a wise choice.

You can select a great value reverse osmosis system with a re-mineralization stage for improving the flavor of your water from my Recommended Reverse Osmosis Systems.

But I just want cleaner tasting water! What size reverse osmosis system is best for me?

Great! This is just what a reverse osmosis system is for.

Any quality reverse osmosis drinking water system will remove many impurities from your water.

For many people, a larger size reverse osmosis system will just have features and functions that they will NEVER use and are a waste of your money.

A small and simple reverse osmosis system will still remove impurities just as well as a larger, more expensive system. Providing that the system uses a quality reverse osmosis membrane, the quality of the water will generally be the same no matter what size the reverse osmosis system is!

If your water does have a taste to it but you want it to taste purer, a simple reverse osmosis system with or without a mineralization stage would fit you perfectly.

What is an acceptable TDS in drinking water, and will any size reverse osmosis system make my water healthier?

As per NSF International, TDS in drinking water above 500 ppm is not considered to be harmful, but may cause staining on water fixtures and may have a salty or other undesirable taste to it. (Source)

How much overall TDS acceptable in water can be a matter of preference.

Some people enjoy the taste of their water with 200 TDS which is considered to be an excellent level of TDS in drinking water.

Other people may want their water to be as tasteless as possible, and therefore they would prefer drinking water with a much lower TDS range.

Many people misunderstand what TDS in their water really means and what level of TDS is considered good or bad.

TDS (Total Dissolved solids) in water is an approximate amount of the total dissolved solids that are contained in a sample of water.

Is TDS the amount of salt in my water?

Although TDS is often mostly salt in the water, salt is not the only dissolved solid that may be indicated by waters TDS reading.

Many people also incorrectly think that TDS is unhealthy solids dissolved in their water and that the lower the TDS the better.

In fact, many dissolved solids in water are beneficial to our health, and many others are not considered to be at all harmful at moderate levels.

To test for your waters Total Dissolved Solids, you can get this TDS meter that will give you your TDS reading in just seconds.

Yes, a high level of dissolved salt in your water is not considered to be healthy, and some other solids in your water may cause spotting on your glassware and water fixtures, but having dissolved solids in your water is perfectly natural.

If you are not happy with the taste of your water because of a high level of TDS in your water, even a simple reverse osmosis drinking water system will greatly reduce the total dissolved solids in your water.

How many stages of filtering do I need?

When it comes to filtering your water to make it better tasting and healthier for you and your family, you certainly don’t want to cut corners, but that doesn’t mean you need to go way overboard either.

I put together an article on The Stages Of A Reverse Osmosis System to help you understand which stages may be best for you.

A simple size reverse osmosis system will usually have only 3 stages

The first stage is either a sediment filter to filter out dirt and debris if your water is coming from a well, or a carbon filter to remove the chlorine if your water comes from a municipal water supplier.

This first stage is mostly to protect the systems’ membrane from clogging or being damaged by chlorine.

The second stage will be the reverse osmosis filtering of the dissolved solids from the water. This is the primary process of the system and does not vary significantly from one system to another.

The last stage of a basic reverse osmosis system will normally be a carbon filter to improve the taste of the water and reduce any unpleasant odors.

Larger sized reverse osmosis system stages for municipal water

For municipal water, you may want an additional carbon block pre-filter or a sediment filter if you do not already have one for your whole house.

If your municipal water is low in total dissolved solids, to begin with, and you would like to add a little flavor to your water, a mineralization stage is available on many reasonably priced reverse osmosis systems.

Additional reverse osmosis system stages for well water

Most reverse osmosis systems have a sediment filter as their first stage to protect the system from dirt and debris, but not all come with a carbon pre-filter to remove any chemicals that may be in your well water.

A reverse osmosis system with both a sediment pre-filter and a carbon filter before the reverse osmosis stage will help to protect the reverse osmosis membrane from debris and chemicals that could damage the systems’ membrane.

Also, if you are concerned with organic material being in your well water, a reverse osmosis drinking water system that has an ultraviolet purification stage will help to sanitize organic organisms in your drinking water.

Some well water is low in dissolved solids even without the use of reverse osmosis.

If this is the case with your well water, and you don’t want your water tasting flat and dull, a reverse osmosis system with a mineralization stage will leave your water flavorful and refreshing.

Should I get a counter-top or under sink reverse osmosis?

From a technical standpoint, both counter-top and under-sink reverse osmosis systems will work equally well for removing dissolved solids from your water.

Why you may consider a counter-top reverse osmosis drinking water system

Highly portable:

If your a renter or simply don’t know if you will want to have a reverse osmosis system in a certain location for a long period of time, a counter-top model can be installed in very little time and can be removed just as quick.

Very easy to install:

A counter-top reverse osmosis system often requires no drilling or plumbing, and in many cases, you need almost no tools at all to install your system and start drinking better water.

Compact design:

Because the system is designed to be placed on a counter-top, the design is extra compact and low profile. This helps to provide plenty of quality water without dominating all of your kitchen counter space.

Why most people prefer an under the sink size reverse osmosis drinking water system

Out of sight, and not on your counter:

Although counter-top reverse osmosis systems are compact, they still stick out like a sore thumb sitting on your counter-top. An under the sink model is hidden away underneath your counter with only the faucet visible.

Even the faucet can be replaced with one that better matches the decor of your kitchen, making it fit in as if it was meant to be there the whole time.

Find the perfect faucet to match your look from my recommended Deluxe Reverse Osmosis Faucets.

Larger size water storage tank:

The fact that a counter-top reverse osmosis system is smaller and can’t store as much water means that there is less water readily available when you need it.

A full-sized under sink reverse osmosis system normally comes with a storage tank that will keep a few gallons of water ready to go whenever you want it.

You can even easily up-grade to a larger storage tank if you require a larger amount of ready to drink water.

Either way, the system should have a sediment pre-filter if you have well water, and a carbon pre-filter if you receive chlorinated water from a municipal water source.

How much reverse osmosis water do you expect to use each day?

People are more active than ever before, and we are paying much more attention to proper hydration than ever before. And people that use a reverse osmosis drinking water system are drinking more and more water each day.

It is recommended that we follow the 8X8 water rule. This rule states that we should drink 8 ounces of water 8 times a day for a total of 1/2 of a gallon or about 2 liters.

If you love to cook, you will most likely use plenty of your reverse osmosis water for rinsing vegetables, cooking pasta, and making soups and other great dishes.

How much reverse osmosis water you will use for cooking will vary, but you should consider this when choosing the right reverse osmosis system for your home.

What size reverse osmosis system do I need for my family of 4?

I have found that the average family of 4 will use up to 2 gallons per day of reverse osmosis water for things other than just drinking. That equates to about a half a gallon per day, per person.

Put these two primary uses of reverse osmosis water together and it works out to approximately 1 gallon of reverse osmosis water per person, per day.

This means that a family of 4 will use about 4 gallons of reverse osmosis water per day.

Many reverse osmosis systems will come with a storage tank that is referred to as a 4-gallon tank, but that is not how much water the tank will actually hold.

For more details, check out my article “How Much Water Does An RO Tank Hold?“

But it’s important to understand that a reverse osmosis drinking water system will refill (top off) the water in the storage tank after just a small portion of the water has been drawn from it.

This varies slightly from system to system but they are all pretty much the same.

Because the system is replenishing the water supply regularly, the amount of reverse osmosis water available per day is much more than the amount of water that the storage tank holds when it is full.

Some reverse osmosis systems will state that they are capable of producing 75 or even 100 gallons of reverse osmosis water per day. But more than likely you will not be using anywhere near that amount of water per day.

So think about your reverse osmosis needs before purchasing a reverse osmosis system that can produce way more water than you would possibly need.

More RO Gallons Per Day (GPD) can mean lower quality water.

The process of reverse osmosis involves the forcing of water through a semi-permeable membrane in order to filter out dissolved solids in the water.

In this process, solids that do not go through the membrane are rinsed away to waste along with some of the water.

In order for a reverse osmosis system to produce more product water per day, it will have to use a larger membrane or a membrane that will allow more water flowing through it.

This can mean a larger overall system, lower quality water, and more wastewater.

Since many reverse osmosis systems can deliver as much as 50 gallons of reverse osmosis water per day, a high volume reverse osmosis system is rarely needed in the average home.

Even a busy family of 5 will generally not use more than 25 gallons of reverse osmosis water per day. And that includes drinking and food preparation.

So a high volume reverse osmosis system is not often required.

What many homes would benefit from is a larger reverse osmosis water storage tank to have more reverse osmosis water ready for use when it is needed.

You can choose the perfect sized storage tank from these Recommended Storage Tanks that will fit your water volume needs.

Do more stages on a large reverse osmosis system mean that it wastes more water?

With each additional filter or stage on a reverse osmosis system, there will be additional back pressure on the water flowing through it.

This resistance against the water flow will reduce the pressure needed to force the water through the system’s reverse osmosis membrane.

When the pressure of the water going through a reverse osmosis membrane is low, less water could be forced through the membrane, and therefore there may be more water discharged to waste.

For the most part, the amount of water that is used to rinse away the unwanted contaminants from your water will not vary much from one reverse osmosis system to the next.

If the water pressure in your home is good, any reverse osmosis system should work fine.

Are you going to be installing your reverse osmosis system yourself?

Most reverse osmosis systems are actually quite easy to install.

In many cases, all you need to do is add a small valve to the cold water supply underneath your kitchen sink, and drill a small hole into your sinks plastic drain pipe.

The faucet for the reverse osmosis system can easily be installed using one of the existing holes that you might already have for your water sprayer or that soap dispenser that you never use anyway.

You will only need very basic tools, and the instructions are usually very easy to follow.

To make a long story short, if you are at all handy around the house, you should be able to install a reverse osmosis system yourself in just a few hours.

If you decide that you don’t want to install your new reverse osmosis system yourself, your plumber or a good handyman should be able to do it for you at a reasonable price.

How much did you plan on investing in your reverse osmosis water system?

This is always a big question on anybody’s mind when they are preparing to buy a reverse osmosis drinking water system, but it doesn’t really have to be!

Sure if you want an expensive reverse osmosis system so you can brag about it to all your friends, they are out there.

You can spend in excess of $2,000.00 for a reverse osmosis system with all the bells and whistles, or you can get the same reverse osmosis process to give you great tasting water for just a few hundred dollars.

Since I don’t believe that most people need an expensive reverse osmosis system, I have selected a few Highly Recommended Reverse Osmosis Systems, that I believe will fit any household situation.

Are you planning on having reverse osmosis water going to your refrigerator?

Having reverse osmosis water dispensing from your refrigerator and for your ice maker is a great convenience, but spending your reverse osmosis water to thin can cause a drop in water pressure.

If you are considering running reverse osmosis water to your refrigerator, distance can make a difference.

An ice maker may not operate correctly if the water pressure feeding it is too low. The cubes may come out small, hollow, or not at all.

Keeping the tubing length to a minimum will help minimize pressure loss and help refrigerator ice makers work better.

Just leave enough slack so that you can move the reverse osmosis system and refrigerator around when you need to.

When a refrigerator is more than just a few feet away from the reverse osmosis system, I recommend installing the storage tank at about the halfway point between the reverse osmosis system and the refrigerator.

This can help the tank feed both dispensers with less pressure loss to either one.

Also, replace any filters in the refrigerator with a dummy cartridge or remove them entirely if you can, to allow better water flow from your reverse osmosis system.

Sometimes installing a separate storage tank just for your refrigerator is the best way to go. You don’t have to use the same size storage tank as the one that came with your reverse osmosis system.

A slightly smaller reverse osmosis storage tank will be large enough for most refrigerator water demand. You will just need to install a “T” in the water line to supply both tanks.

What have other buyers said about the reverse osmosis system that you plan to buy?

I almost never buy anything without at least checking some reviews about something that I am interested in. Thank goodness that reviews are very easy to find.

Although many things don’t really need to have reviews, you can often find a review or at least a rating about nearly everything that you would buy for your home, and a reverse osmosis system is no exception.

Since so many people are buying nearly everything that they are looking for on-line, finding reviews from other people that have already bought what you are about to buy is very easy.

I only recommend online products to my customers that I know have excellent reviews and plenty of them.

If you look at my Recommend Reverse Osmosis Systems, you will see that every system that I recommend has many positive reviews.

Now, I might recommend an item here and there that has very few reviews, but it is likely an item that I personally use that doesn’t really need a review.

In any case, and no matter which reverses osmosis system you choose, look for positive ratings and take the time to read at least some of them so that you feel comfortable about making your purchase.

How big are reverse osmosis drinking water systems anyway?

Reverse osmosis drinking water systems come in several sizes, but generally, they range from about 13 – 19 inches high, 4 – 6 inches deep, and 14 – 19 inches long.

An average reverse osmosis storage tank will range from between 9 inches in diameter x 13 inches high for a smaller 2-gallon tank, up to about 15 inches diameter x 23 inches high for a 14-gallon tank.

Can I get a larger storage tank than the one that comes with the system? And how big are they?

Absolutely! Most reverse osmosis drinking water systems come with a very standard sized tank that is usually referred to as a 4-gallon tank.

But that is not how much water the tank will hold!

A reverse osmosis water storage tank that says it is a 4-gallon tank will only hold about 2 1/2 gallons of ready to use water. The rest of the tank is full of air which is used to push the reverse osmosis water out of the tank.

If you think that you would like to have more reverse osmosis water ready for you when you need it, you can always upgrade to a larger (or smaller if space is an issue).

I have selected a few very common sizes of reverse osmosis storage tanks that will work great for any home, and are compatible with virtually any reverse osmosis system.

Can I use a larger storage tank and lay it down on its side?

Yes, you can! A standard type air charge water storage tank will work fine standing up as well as laying on its side.

Since the bladder that holds the water is in the center of the tank with pressurized air surrounding it, it will work well either way.

How complicated will it be to maintain?

Much less complicated than you think! Reverse osmosis drinking water systems pretty much take care of themselves.

The only maintenance that you as the homeowner has to do is change the filters on the system every so often depending on your water situation.

Read more about How Often You Should Change Your Reverse Osmosis Filters, and how to do it.

Changing the filters is a snap, reverse osmosis systems come with detailed directions on how to do it step by step. You will be able to change them like a pro in no time.

Other than that, there is basically nothing that you have to do except enjoy your reverse osmosis water.

What future costs will you have to consider?

Pretty much just having to get new filters when you need to change them, and a new membrane every few years.

Some of the more expensive reverse osmosis systems can charge as much as $190.00 for a set of filters for their systems, but I have selected a few Recommended Reverse Osmosis Systems that use filters that are far more reasonable than that.

Most reasonably priced reverse osmosis systems will use filters that are around 50 – 70 dollars for the complete set, and you don’t have to order them from a dealer that can raise the price whenever they please.

The filters are also very easy to change yourself, so there is no expensive service call needed, just so you can have quality water to drink.

Can you maintain your new reverse osmosis system yourself?

Absolutely, you can maintain your new reverse osmosis yourself. All you really have to do is some very simple procedures and your reverse osmosis system should last a very long time.

Is a small size system easier to maintain?

The size of reverse osmosis often relates to the number of filtering stages that are being used in the system which means more filters to change. So the smaller-sized reverse osmosis system you have usually means fewer filters to change and less maintenance.

Larger sized reverse osmosis systems can have 10 or more filters and cartridges to replace on a regular basis, and many of these filters and cartridges may not be making your water better at all.

Regular filter changes:

Depending on the quality of the water going into your reverse osmosis system and how much water you use from it, you will have to change the filters occasionally.

Often changing your reverse osmosis filters is only a once a year activity, and if your water is relatively good to start with, and you only use your reverse osmosis water for coffee and tea, you may only have to change the filters every two years.

See How Often Should I Change My Reverse Osmosis Filters for details.

What if I forget to change my filters?

That’s not usually a problem. We all have busy lives, and sometimes we forget to do things that we don’t do regularly.

I often suggest changing your reverse osmosis on an annual basis, and to do it right before or after an annual event that you won’t forget.

Right after your birthday, your favorite holiday, back to school, whatever annual event that works best for you.

But if you find that you didn’t change your filters as planned, there is not likely any damage done. Changing your reverse osmosis filters a few weeks, or even a few months late is not likely to be a problem.

Change them A.S.A.P. and check the water Total Dissolved Solids (TDS) in the water with a TDS Meter.

If the TDS from your reverse osmosis faucet is 10% or less than the water coming from your regular tap, you should be just fine.

Change the reverse osmosis membrane when needed.

Changing the reverse osmosis membrane may sound like a complicated technical procedure, but it really is not that hard at all. It is pretty much just like changing a regular filter with just a few extra steps.

First of all, for most reverse osmosis systems, the reverse osmosis membrane does not get changed every time that you change the filters.

Even though changing the membrane frequently should not cause any issues, it usually only needs to be replaced every few years, or when the quality of the water diminishes.

Your owner’s manual should have detailed instructions on how to change the reverse osmosis membrane, so when you get your new reverse osmosis system, be sure to put the instructions and manual in a safe place.

Sanitization of the system:

Your new reverse osmosis system comes out of the box nice and clean inside and out. But after a while, there is a chance that bacteria can develop inside of the chambers and tubing of the system.

Even though a reverse osmosis drinking water system is an enclosed system, dissolved oxygen in the water can settle on the walls of the storage tank, tubing, and even the faucet.

Where you find oxygen and moisture, there can be bacteria.

This sounds rather gross, but it is easily avoided by following a simple sanitization process when you change the filters of the system.

I wrote this article on How To Sanitize Your Reverse Osmosis System to provide step by step instructions for you.

By using a sanitizing additive when you change the filters, you can sanitize the entire system from the very beginning, right to the end of the faucet.

Re-pressurizing the reverse osmosis water storage tank:

When selecting a reverse osmosis system, it is a good idea to take a close look at the storage tank to see if it’s air valve is on the side or bottom of the tank.

You will at some point need to add air to the tank so that it can push out the water stored inside of it. See my article on Re-Pressurizing Your RO Storage Tank for details.

To do this, you will have to attach an air pump to the air valve on the tank. Having the air valve on the side of the tank makes re-pressurizing the tank a little easier.

Take care of your other water treatment equipment:

A reverse osmosis drinking water system is designed for filtering out contaminants from your water, but hard minerals, iron, or other minerals in it can be damaging to the reverse osmosis membrane and other stages of the system.

If you have hard water and a water softener to remove the hardness, make sure that the water softener is working correctly so that the water that your reverse osmosis system is soft and free of iron.

This will make your filters and your entire system work better and last longer.

Is a water softener needed to use a reverse osmosis system?

No, you don’t. A reverse osmosis system will actually remove hardness from your water, but in doing so, you may greatly reduce the lifespan of your reverse osmosis membrane.

Iron, on the other hand, can quickly clog your reverse osmosis filters and membrane. This will lead to a loss of pressure and frequent filter changes.

Reverse osmosis is a very nice addition to your home’s water treatment when you have a water softener.

See why it might be beneficial for you to have a reverse osmosis system when you have a water softener in my article I Have A Water Softener, Do I Need Reverse Osmosis?

To sum up:

The ideal reverse osmosis system for you and your family will depend on the amount of water that you expect to use, and what is in the water that you have supplying your home.

If the physical space that the system will take is an issue, you can install the system and the storage tank in two locations close by to one another or even install the whole system in another location away from the sink where it will be used.

Determine which stages of filtration that you feel would most benefit you and select a reverse osmosis system that properly fits your needs.

Once you know what is important to you in a reverse osmosis system, check out my Recommended Reverse Osmosis Systems to get the right one for you.