What Is Reverse Osmosis (for Dummies)? A Simple Explanation
Written by: Gene Fitzgerald // Last Updated: Jun 1, 2023
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With reverse osmosis water purification becoming so popular lately, you might be wondering how the process works.
Well, understanding reverse osmosis in great detail is not necessary if you’re planning to install a filtration system in your own home.
However, it can still be useful to at least know the basics and have a rough idea of what’s going on behind the scenes. Though it might sound very complicated, reverse osmosis is actually pretty simple, all things considered.
Here is a brief rundown of how it works – reverse osmosis for dummies!
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Key Takeaways
Here is a simple explanation of reverse osmosis for dummies: Reverse osmosis is a water purification process that separates contaminants from drinking water using a membranes with tiny holes. The membrane is like a sieve which filters the water under pressure removing everything except water itself.
What Is Reverse Osmosis (for Dummies)?
So, what is reverse osmosis for dummies?
A simple definition of reverse osmosis, short RO, would be that it’s a water purification method. It relies on a membrane with very tiny pores which don’t allow much to pass through them other than water. Water just has to be pushed against this membrane at high pressure, and that’s pretty much all there is to it.
If this sounds suspiciously simple, it’s because it is. That’s one of the beautiful parts of reverse osmosis. It doesn’t require any complicated technology or a lot of energy. You just need to be able to create enough pressure to force water through that membrane.
This process has many advantages over other types of water filtration, while at the same time having very few disadvantages. The main negative consideration with regards to reverse osmosis is that it can waste a lot of water. Even that is a minor inconvenience compared to the problems created by other filtration systems. And when you factor in the low maintenance requirements, reverse osmosis is a very elegant approach to providing your home with filtered water.
How Reverse Osmosis Works Explained Simply
But how does forcing water through a membrane actually filter it?
The basic idea is the same as with any other porous filter. The pores on the membrane are so small that only water molecules can pass through them, much like a very fine sieve. Or at least that’s the basic idea. In reality, some minor amounts of contaminants might also make it through. However, even with that in mind, reverse osmosis still removes as many as 95% to 99% of contaminants in your water.
The main component of a reverse osmosis system, as we mentioned above, is the RO membrane. The material is typically rolled up into a cylinder creating multiple layers. Water is pushed against the middle of the cylinder and is separated into two streams – purified and dirty water.
The dirty water gets sent away, while the purified water makes its way to your faucet or any other point of access in your home.
A Simple Explanation of Reverse Osmosis for Kids
What would be a simple explanation of reverse osmosis for kids?
Imagine the following: get a tub, or another container, and fill it with water. Place some sort of barrier with very tiny holes in the middle of the container, separating the water into two compartments. The holes must be so tiny that you can’t even see them with your naked eye. Now if you added some kind of contaminant – like salt – to one half of the tub and mixed it well, what would happen?
Naturally, the solutions would try to equalize the level of salt in both parts of the tub. The salt itself, however, is too large to make its way through the barrier. So water starts to pass through the barrier, from the less to the more salty side. And this process will continue until the level of salt on both sides of the barrier equalizes. This process is known as osmosis and it happens all around us in nature.
Reverse osmosis takes the same principle and inverts it. The main difference is that water will only naturally flow from the side with a lower salt concentration to the higher concentrated one. To change that, we must force the water in the other direction. This is done by introducing pressure to the system. If you forcefully push water from the contaminated side against the barrier, the water will start to make its way through and end up on the other side. Eventually you will have little water left on one side carrying all the salt, and the other side is pure water.
What Are the Advantages and Disadvantages of Reverse Osmosis?
Reverse osmosis is a fantastic way of purifying water. In terms of effectiveness, it’s pretty much the best there is. Only distillation comes close, but it’s not nearly as convenient as reverse osmosis. That said, the process does have some minor disadvantages that are important to understand. Here is a brief overview of the ups and downs of reverse osmosis.
Pro: Enjoy Pure, Clean Water Whenever You Want It
With reverse osmosis, you will always have pure clean water on demand. Even though the filtration process is pretty slow, you can compensate for that by adding a storage tank. This is a common element of many rivers osmosis systems, especially in larger households. This can even allow you to fill up bottles for camping and other travel purposes on short notice.
Pro: Always Have Purified Water Available
You will never have to worry about having enough fresh water stored. As we mentioned above, a large storage tank can pretty much negate that issue completely. Of course, storing water for too long can make it develop a stale taste, so you have to be careful about balancing this.
Pro: May Help You Drink More Water
If you’re not used to drinking a lot of water, that might be because you’re subconsciously avoiding it due to its unpleasant taste or smell. This is often caused by various types of contaminants. Drinking reverse osmosis water means that you might rediscover your love for staying hydrated. It’s not rare for people to start drinking a lot more water than they usually do once they have installed a reverse osmosis system in their homes.
Pro: Stop Buying Bottled Water All the Time
If you prefer filtered water, you might be used to buying a lot of bottled water from the store. While this can work, it’s far from an ideal approach. Water bottles are heavy and take up a lot of space. Not to mention the pollution they create. If you have a reverse osmosis system at home, you will never have to buy another bottle of water again. In fact, you might even enjoy healthier, cleaner water than you did with bottled products. That’s because some bottled water producers don’t even filter their water – they just sell straight tap water.
Con: Wastes Some Water
Probably the biggest disadvantage of reverse osmosis is that it wastes some water in the process. This is unavoidable due to the way reverse osmosis works. You shouldn’t completely write off that water as lost though. You can reuse it for other purposes, like watering your garden or washing your clothes.
Further Reading:
Con: Removes Some Healthy Minerals
As we mentioned above, reverse osmosis is a very thorough mode of filtration. It effectively removes pretty much every contaminant from water. Unfortunately, this occasionally includes some useful elements. Water naturally contains various minerals like calcium, which are healthy when consumed in moderate amounts. If you switch to reverse osmosis water, you might have to balance your diet in another way.
Con: Not Portable
There is no easy way to make a reverse osmosis system portable. This means that you can’t bring it with you when you’re out camping, for example. What you can do, on the other hand, is fill up several large bottles of RO water and bring them with you. It’s not ideal, sure, but it’s better than drinking unpurified water. There are some dispenser-type models available on the market, but those are still not perfect and are not recommended for taking with you on the go.
Con: Takes Up Some Space
You have to make some room for your reverse osmosis system. In addition, you might need to get a dedicated faucet for it, which will take up some space on your countertop. Even that’s negligible compared to the amount of space taken up by other water filters though. It’s much better than having a large, bulky dispenser right in the middle of your countertop.
Con: Slow Filtration
Reverse osmosis is a slow process. It can take a while to filter even small amounts of water. This means that you have to plan ahead to ensure that you always have some fresh water available. But as we mentioned earlier, you can easily get rid of that problem with a simple storage tank. You usually don’t need to go too large with this – a few gallons should do the trick for the average household. Of course, if you live with more people in your home, you might want to consider investing in a larger storage tank, or even an additional reverse osmosis system.
If you have any thoughts about the question, what is reverse osmosis in simple words, please don’t hesitate to leave a comment below!
About the Author Gene Fitzgerald
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