Reverse Osmosis water filter system is one of the most popular water filter systems used in both commercial establishments and residential homes nowadays. Since it can remove almost all types of bacteria and contaminants, its popularity is due to its extensive filtering coverage and versatility.
With the increasing need for this type of water filter system, the manufacturers are trying to create more advanced variations of these. One RO system type that has garnered the attention of most homeowners is the Tankless RO Systems (also called as Direct Flow Reverse Osmosis Water Filter System).
What is it the Tankless RO System? How does it differ from the traditional RO water filter systems that we know of? In this article, we will talk about Reverse Osmosis Tank Vs. Tankless. If you want to determine which of the two is most suitable for your needs, keep on reading!
What You Need to Know About RO Systems with Tank
Let us begin with the traditional Reverse Osmosis water filter systems or the RO systems that come with a tank.
How Does it Work
Traditional Reverse Osmosis systems use pressurizes tanks to store purified water until there is a demand for it. As a hydropneumatic tank, it stores not only water but pressurized air as well. Because of the presence of pressurized air, the tank helps the water filter system to deliver clean water fast and on-demand without no need for a booster pump.

Inside the tank, you can find a water chamber and an air chamber that is divided by a bladder at the center. Once the filter system starts to feed water into the tank, the air inside the chamber gets compressed due to the weight of the water.
When the air is compressed, the pressure inside the tank increases too. This is the pressure that will propel the water out of the tank and into your faucet, which you can gain access to once you turn the faucet on.
The RO tank offers two essential functions to the operation of the RO system. Aside from delivering the water, you need on-demand, the tank also aids in maintaining pressure throughout the filtration system and monitoring the system’s line pressure. Because of this, it assists in activating the on/off cycling of the filter.
The RO system features a sensory valve that stops the production of water once the pressure inside the tank reaches 2/3 of the line pressure. Once the said pressure line is reached, it will facilitate the valve to move to its closed position to cease all water operations.
Advantages of RO Systems with Tank
Since we have been used to the functions of the traditional RO system, there is no doubt that it comes with a lot of advantages that made us love it. Here are some of them:
- Traditional RO systems are a lot more affordable than tankless systems.
- Since it is pressurized, there is no need for you to buy a booster pump.
- The tank serves as the storage container for water, which would come handy in certain situations.
- It works with the system’s line pressure and helps in facilitating the filter’s on/off cycling function, which can help in saving water and money.
- This is widely available.
Disadvantages of RO Systems with Tank
But of course, the traditional types also come with a few disadvantages. These are the very reasons why companies continue to tweak their designs and come up with other variations.
- Since it uses only one filtration membrane, it may not be able to filter out carbon dioxide.
- The RO tank may take a lot of space in your home.
- When water is stored for a prolonged period, it may taste differently.
What You Need to Know About Tankless RO Systems
Tankless Reverse Osmosis Water Filter Systems are the latest additions to the types of RO systems that are available in the market these days. From its name, we can say that these do not come with the storage tank that most RO systems have.
Considering this, how will it differ from the traditional RO systems that we are used to? Here are some of the things you need to know about Tankless RO Systems.

How Does it Work
Tankless RO systems work almost the same as the traditional RO systems. Their only difference is this type has no tank. In short, there is no storage space for the water, so it is considered to be smaller than traditional RO systems.
Aside from this, another difference that this type has with the traditional ones is the number of RO membranes that it uses. The conventional RO systems use only a single RO membrane. The tankless ones employ multiple membranes so it can filter more contaminants.
Since these systems do not have storage tanks, these depend on the incoming water pressure when it comes to pushing the water into the filtration medium of the system.
All tankless RO systems have required water pressure values to operate properly. If the water pressure inside your home is not high enough, this may become an issue.
To address this, you may need to buy and install a separate booster pump, which can increase the water pressure and ensure that the water will be delivered to the filtration beds at a reasonable rate.
Advantages of Tankless RO Systems
Tankless RO Systems were developed to address some of the issues that traditional RO systems have. With that in mind, the use of these systems offers the following benefits:
- Without the tank, tankless RO systems occupy less space at home. Its small size would be suitable for small families. For people living on rental houses or apartments with minimum space, the benefits of this RO system are huge.
- Since it has no water storage tank, it delivers water instantly.
- Because the water is not stored in a tank, tankless RO systems may deliver better-tasting water.
- Minus the tank, tankless RO systems produce water only when it is needed. Therefore, it is economical.
Disadvantages of Tankless RO Systems
But of course, no system is perfect. Even with the add-ons and tweaks, this system also has its cons. There are as follows:
- Tankless models are quite expensive.
- Since these systems use multiple filter membranes, you would need to replace them all. As a result, replacement and maintenance would be costly too.
- The absence of a storage tank may become a disadvantage in some situations.
Reverse Osmosis Tank Vs Tankless: Which Should You Choose?
There you go. These are all the reverse osmosis tank vs tankless information that you need to know. But which is the one for you?
Considering the information that we have mentioned in this article, the main difference between the two is the size and the presence of the tank.
The small size of this type of RO system makes it the most suitable option for small families, people who are renting houses and apartments.
If you want to save space, enjoy an extensive filtration process, and most importantly, have enough money to spare, then you may want to consider getting a tankless RO system.
And even though it is small, its filtering power is amazing, thanks to its multiple filtration membranes.