Reverse Osmosis Systems

Reverse osmosis (RO) systems are one of the best water filtration solutions for a wide range of contaminants. The filters last long and you always have fresh, clean water on demand.

Most people choose RO systems that are installed under the counter.

But did you know, that more portable, countertop reverse osmosis systems exist as well?

Lean more about reverse osmosis water filter systems and explore your choices.


  • Very effective
  • Fast and Convenient
  • Easy to use for children and elderly persons
  • Filters last from 6 month to 1 year.


  • Installation requires DIY skills (or a plumber)
  • Gurgeling sound while tank refills if you use an air gap faucet

Price Range: $150 - 600

See our reviews of the best reverse osmosis systems.

reverse osmosis faq

Reverse Osmosis FAQs

How long do RO holding tanks last?

RO holding tanks are metal or plastic containers with a butyl bladder inside. Assuming your tank is not rusty or otherwise damaged, the most likely part to show wear is the bladder inside.

Many manufacturers give you a 5 year warranty on their tank. While some tanks fail earlier, others last six to eight years.

How often do you need to change a reverse osmosis filter?

Pre and post filters last anywhere between 3 months and 1 year, some even longer. It depends a lot on your water quality and the size and type of filter. RO Membranes usually last 2 to 3 years.

How do you change reverse osmosis filters?

There are two types of filter systems: one, where the housing is part of the filter and another type, where the filter sits in a separate housing. In both cases, you unscrew the filter housing and replace the filter.

For some systems you need the housing wrench, that came with your system. For detailed instructions on how to change a reverse osmosis filter, check out our DIY post.

Can I connect my RO system to a refrigerator?

Yes, you can. And many manufacturers offer an add-on, that makes it easy to do so.

Just keep in mind, that the water line between your RO unit and the fridge should not be too long. In case there are pressure issues, consider to add a pressure pump to your system.

Is it true, that reverse osmosis wastes a lot of water?

As so often, the answer is, it depends. All RO units need water to wash away contaminants regularly. This water is lost for consumption.

Modern systems can have waste water ratios of 1:1, which is really low. Older systems often need more water.

Additionally, the water pressure plays a role in the amount of water lost for drinking. Higher pressure usually equals a lower waste water rate. That is one reason, why some people install a pressure pump.

How much do you have to spend on maintenance per year?

This maintenance cost of a reverse osmosis system depends on the price of replacement filters for your system. This is why we list the price of replacement filters in our reviews.

If you buy a budget system, the amount you have to spend on new filters often make it a less than good deal. When you plan to buy a new reverse osmosis system, do not only look at the purchase price for the system. Check also how long the filters last and how much you would have to pay for them.

Is distilled water cleaner than reverse osmosis water?

Distillation and reverse osmosis are both two very effective techniques to clean water, but not for all contaminants.

For everything with a lower boiling point than water, distillation is not effective. That includes chloramine, a disinfectant used by many public water systems to fight bacteria.

Wrap Up

Reverse osmosis systems are a convenient and safe choice for nearly all water quality problems. They are able to reduce everything from chlorine and fluoride to pesticides. Even radioactive contaminants have little chance to contaminate your drinking water any longer.

Once installed, they are easy to handle by small children or elderly people. No need to remember to refill and readily available purified water are more reasons to go for a RO system.

While reverse osmosis units do not need electricity, these systems waste a certain amount of water. The waste water ratio can be as low as 1:1 or as high a 1:5 depending on model.