Reverse osmosis systems are fully functional when they are installed, but can also be improved to give you better water pressure and consistency. Installing a pressure gauge, booster pump and pre-sediment filter will have the greatest improvement effect on your reverse osmosis system. But regular cleaning and flushing of the unit will also improve the efficiency of the system.
Having a reverse osmosis (RO) system gives you the ability to produce purified drinking water all the time. But, sometimes they don’t always work as efficiently as you’d like.
In this article we discuss some simple improvements you can consider to improve your RO that are relatively cheap and most can be done yourself.
16 Ways To Improve Your Reverse Osmosis System
These 16 ways to improve your reverse osmosis system are not in any particular order of importance, so make sure you check out each one.
Water Purification Guide also has a detailed troubleshooting guide if your reverse osmosis indicator is flashing red and how to fix it available here.
1. Add a pressure gauge
Ok, this one is kind of obvious. Low water pressure is one of the most common issues that reduces efficiency in reverse osmosis systems.
The optimal water pressure feeding into your household reverse osmosis system should be 40 psi or greater (Voigt et al., 2013). To efficiently produce high purity water, reverse osmosis systems require a water pressure of 60 psi, but no greater than 80 psi.
If water pressure is near or below 40 psi, water will not get forced through the semi-permeable membrane that filters out dissolved solids and other contaminants, which reduces flow and water quality.
Not all reverse osmosis systems come with a water pressure gauge. If yours doesn’t, I recommend this water pressure gauge on Amazon, since these water pressure gauges help buffer vibrations making it easier to read the needle – Install it along the feed line between the carbon filter and RO membrane.
2. Use a booster pump
Booster pumps work by increasing the pressure of the water feeding into your reverse osmosis system.
Low water pressure = Inefficient Reverse Osmosis
Not everyone will need a booster pump, but if you know you have low water pressure, installing a booster pump will probably be the most significant improvement you can make to improve your reverse osmosis performance.
Booster pumps are also commonly used with RO units that require higher water pressures of 60-65 psi including:
- High flow membranes
- Dual membrane units
You don’t have to get too technical with booster pumps, just make sure you choose one with a high enough GPD (Gallons Per Day) rating for your reverse osmosis system.
I like the Aquatec Booster pumps because they are built solid and the 6800 and 8800 types provide ample pressure coverage for most household RO Systems.
If your RO System is designed to produce less than 50 GPD then use the Aquatec 6800 booster pump kit from Amazon.
These are very quiet (quieter than the 8800) and they are rated for RO units under 100 GPD. You can still use them for the larger RO systems – a lot of people do because they are nice and quiet – but you may have to dial it up to the highest setting to get the required psi (usually 60-65 psi).
For RO Systems that produce between 50 and 100 GPD then go for the Aquatec 8800 booster pump kit.
I’ve found buying elsewhere you have to buy the transformer and fittings separately so buying from Amazon is pretty good in this case. They are noisier than the 6800 but they are designed to more easily handle larger RO units (up to 200 GPD).
To install your booster pump, attach it before the RO system.
3. Install a whole house sediment filter
Whole house sediment filters work well as an initial first stage to help remove larger particles such as rust, chunks of scale, sand and fine sand from ever reaching your reverse osmosis system.
Just make sure you buy one with brass fittings, so they last. I like the ISpring whole house sediment filter (Amazon link).
They’re built really well (solid) and just seem to last forever.
If you are on well water they are a great idea as they really help reduce the bulk of sediment entering your RO unit (and the rest of your house).
Reverse osmosis systems are more than capable of removing large sediments, but a whole house sediment filter does the initial grunt work of removing bulk sediments.
Here’s how it helps:
- Improves the lifespan of RO filters
- Reduces clogging in the pre-sediment filter
- Improves the efficiency of the RO
- Reduces wear and tear on the RO system
4. Install a secondary water tank
To improve the flow rate to your faucet or other outlets in your house, install a second water tank.
A second reverse osmosis water tank will give you roughly twice the flow rate as well as doubling the amount of water available (based on installing a similar sized tank to the one you currently use).
Two tanks = Twice the flow rate and water capacity
I’d go for something like this 4 gallon RO tank like this one (on Amazon), since it’s not very expensive and is about the right size to fit in a cupboard or under your faucet.
Quick tip:
If your existing tank and RO are located somewhere like your basement, you will still get improved flow from installing a second tank. But it may not be quite as good as installing it directly underneath your faucet.
How to install a second RO tank:
- Turn off valve from main tank
- Cut the tubing that feeds from the RO to the main tank on a 90-degree angle.
- Add in a Union Tee fitting to the line
- Fit the second tank with an on/off valve and attach some 1/4″ or 3/8″ tubing between the union Tee fitting and the newly installed tank valve.
- Open up the supply line from the RO, turn on both tank valves and check for leaks
By the way, I would suggest John Guest and Mur-Lok if you want really good quality push connect fittings.
5. Drain your storage water tank every 2 weeks
Drain your RO storage tank every couple of weeks. It may sound silly to throw away perfectly clean water, but it may not be that clean. If you haven’t been using much water, you are really only dropping the tank volume a little each time. When the new product water mixes with the old it may not taste as fresh as it could.
So, it’s always good to get in the habit of completely draining your tank every few weeks to make sure you are getting a full tank of clean drinking water.
6. Clean your storage water tank
Over time your RO tank can start to develop slime or mold inside. A lot of people never consider this as they assume that because the water in their tank came from their RO that it stays clean.
Unfortunately, this is not true.
Slime and mold can develop inside your water tank, so it’s always a good idea to give it a good clean and to sterilize it with a dilute chlorine or iodine wash. Honestly, you don’t have to do it often but once every few years should keep your water tasting great and keep any slime or mold build up to a minimum.
7. Install a flush kit
Flush kits are CHEAP!
Flush kits help remove surface deposits from the RO membrane, which substantially increases the life of the membrane, water production rates and quality of your drinking water.
To use them you simply turn the valve that bypasses the flow restrictor, which increases the flow rate over the RO membrane.
All you have to do is remember to manually turn it on every once in a while.
Here’s one on Amazon that’s cheap and easy to install yourself.
8. Add an automatic flush valve
Automatic flush valves for an RO does basically the same thing as a flush kit. The benefit is they do it automatically about once an hour while the RO system is in use.
They substantially prolong the life of the RO membrane – plus the nice part is you don’t have to remember to manually do it yourself.
9. Consider a water softener
Some people INSIST reverse osmosis systems are water softeners. This is not really true. Reverse osmosis systems filter out the hard minerals in water but they don’t actually soften it.
Most of the water in the United States is HARD. This means the water has a high dissolved mineral content, usually calcium and magnesium, which causes scale and reduces the efficiency of your reverse osmosis system.
Scale is calcium carbonate. If you’ve ever been to the beach and picked up a shell or maybe touched hard coral while scuba diving – that’s the same stuff. Calcium carbonate IS HARD!
When scale builds up, it’s difficult to remove and can seriously impair or damage your reverse osmosis system along with all other appliances, pipes and fittings in your home.
Water softeners work by switching out the calcium (and magnesium) from the water with minerals less prone to forming a hard scale – typically sodium.
When you’re buying your water softener to stop scale-forming minerals reaching your reverse osmosis system, keep a few things in mind.
First, an electronic descaler or magnetic water conditioner will NOT cut it.
Both can work by reducing the initial build up or removal of scale from your pipes (See Pečnik et al., 2016; Othman et al., 2019), but they do not remove the calcium or magnesium mineral content from your water. Scale can still build up in your reverse osmosis system and your home.
Second, if your considering a water softener, there are two main types:
- ion exchange water softeners, or
- salt free water softeners (conditioners)
Let’s discuss the differences.
Ion exchange water softeners
As the name suggests, ion exchange water softeners work by “exchanging” scale forming mineral ions (like calcium and magnesium) from water with non-scale forming mineral ions (like sodium).
Benefits:
- Ion exchange is the only TRUE way to soften water
- You have to periodically buy water softener salts
- Protects your whole house from scale
- Protects your reverse osmosis system
- Extends RO membrane lifespan:
| Ion exchange water softener | Reverse osmosis membrane lifespan |
| Yes | 5-7 years |
| No | 2-3 years |
The water flows through the water softener salts (usually beads) and the left-over salty water (sodium and chloride brine) is discharged as wastewater.
Because of the high level of water wastage and discharge of brine water into drains and private septic systems (on-site sewers), it can damage agricultural areas and the environment. As a result, some state communities have (at one time) banned them, restricted their use or have specific rules around where the water can be discharged.
Don’t be too concerned however, just check with the division of water quality in your state community before going ahead and buying one.
Salt free water softeners
Some of the benefits of salt free water softeners compared to ion exchange includes:
- Simple to use – once installed that’s it
- Easy to install yourself
- Does not produce any wastewater
- Does not require electricity to run
- Does not require a regeneration cycle
- You do not need to buy salt
Sounds great right?
However, salt free water softeners do not actually “soften” water as they don’t remove calcium or magnesium minerals. For this reason, they technically function as water conditioners, not softeners. But I thought it was important to discuss them here as you will definitely still see them marketed as water softeners.
Salt-free water softeners (conditioners) cause scale-forming minerals to crystallize on a special membrane inside the water softener tank.
These micro-crystals can eventually break off and travel through your water pipes. This doesn’t mean these systems don’t work – in fact they are designed this way. The micro-crystals that travel through your pipes don’t form scale and will naturally come out or get picked up in a downstream sediment filter (like in your RO).
However, if you have high iron or manganese in your water (like most well-water in the U.S.) this will inhibit the ability of salt-free water softeners to crystallize scale-forming minerals. So, in the presence of high iron or manganese, calcium and magnesium will pass right through a salt-free water softener and can then go on to form scale.
So, salt-free water softeners work well if you are on city water because high levels of iron or manganese are already removed at your municipal treatment plant. However, if you are on well water you are probably much better off with an ion exchange water softener.
How to test for water hardness
If you are unsure if you need water softener, first you should test the hardness of your water.
You really don’t need to spend a lot of money here, just get a simple hardness test kit with multiple test strips. There are lots of good ones and some that are quite expensive, but this hardness kit has 150 test strips and is relatively cheap on Amazon.
If you get scale build up in your reverse osmosis system, kettle, coffee maker, boiler or shower then you definitely have HARD water.
10. Add a carbon post-filter
A carbon post filter polishes the product water as it leaves the storage tank before reaching your faucet. This will remove any last impurities from the product water, or any bad tastes that may have developed if your tank water has been sitting for a while.
For some people it may seem a little overkill, and just an added cost. However, it guarantees high quality and great tasting water no matter what.
Plus, these filters don’t need to be replaced very often!
Compared to the pre-sediment and regular carbon filter in your RO system, the carbon post-filter only has to deal with very pure water that has come from the tank. So, it only has to be replaced about once a year.
11. Use graded density sediment filters
A lot of people think the sediment filter in an RO is not that important and often buy the cheapest option possible. Bad idea. Sediment filters are typically the cheapest filter in your RO, but can severely impact how well the whole system functions and how long the other filters last.
Cheap or aftermarket filters will capture sediment and dirt but can clog really quickly. This reduces the pressure feeding the RO membrane and will affect how the system performs. A clogged sediment filter will also cause the carbon block filter to clog prematurely costing money and time replacing it more often than really necessary.
A good sediment filter has a graded density (also called multi-layer density).
A graded density sediment filter means it has various layers designed to capture different particle sizes, which:
- Captures more sediment
- Reduces clogging
- Reduces pressure drop
- Increases how long ALL your RO filters last
I like the PurePlus 5-micron sediment filter 4-pack because the 5-micron layer has the “Absolute” rating meaning it removes 99.9% of sediments that are 5 microns – That’s awesome!
It also helps protect the more expensive carbon block filter allowing it to last as long as possible.
12. Replace the carbon filter to protect the membrane
Reverse osmosis membranes are easily damaged by chlorine. The main material used in household reverse osmosis membranes are:
- Thin Film Composite (TFC)
- Cellulose acetate (CA)
Most commonly used is the thin film composite type. The thing is thin film composite membranes are easily damaged by chlorine (Nguyen et al., 2017). Chlorine damage compromises the integrity of the membrane and your drinking water. Chlorine also limits the life of the membrane and increases the operating costs of the whole RO system.
So why do they use it?
Well, thin film composite RO membranes are also really good at removing pesticides and herbicides.
In comparison, cellulose acetate materials are chlorine tolerant (Shintani et al., 2007), but they don’t remove pesticides and herbicides so are not as commonly used.
To protect the Thin Film Composite RO membrane from chlorine damage, it’s critical that your carbon filter is well maintained and replaced early and often.
Activated carbon water filters remove free chlorine.
However, once the activated carbon gets old and runs out of “active” sites for the chlorine to be adsorbed (adhere to the carbon), your RO membrane is more at risk of becoming damaged. RO carbon filters usually last around 6 to 12 months but is highly dependent on the quality of your unfiltered water.
- If you have high chlorine city water = replace every 6 months
- If you have low chlorine water = replace no later than 12 months
If you want to know a lot more about activated carbon filters, check out this article I wrote – how long activated carbon water filters last.
13. Install a flow monitor
Installing a flow monitor, also called a filter monitor, allows you to keep track of the total amount of water passing through your RO system.
This allows you to get the most use out of your filters by not changing earlier than you need to. It’s also a good reminder when to change the filters as each one will have a maximum number of gallons it can be used for.
Just don’t forget, that all the water passing through the unit counts. So, if your filter is supposed to be good for say 10,000 gallons, that includes both wastewater and product water – not just the amount that came from the storage tank. This is where adding a flow monitor can help.
14. Use a TDS meter
A great way to tell if your reverse osmosis system is functioning properly is to measure the concentration of total dissolved solids (TDS) in the feed water (in flow) and compare it to the product water (out flow) TDS.
Ok, so there’s two ways you can do this… using a manual (hand-held) TDS monitor or using an automatic TDS monitor.
Manual TDS monitors come in all kinds of fun colors – Not that it makes any difference to the readings. But what does matter is you should make sure it comes with Automatic Temperature Compensation (ATC). The ZeroWater TDS meter is quite good.
Without an ATC, variations in water temperatures can wildly distort the TDS reading.
Automatic TDS monitors are a bit easier to use. You just connect it once and away you go. They have in-line probes that attach to both the feed water and product water lines. So you just flick a switch and you can read the TDS from either line. They don’t come with ATC, so the way I get around this taking the reading while the RO is running as the temperature difference remains fairly constant.
I really like this HM Digital in-line TDS monitor, it’s not terribly expensive and it gets amazing reviews.
Generally, reverse osmosis systems should be rejecting between 90% and 95% of the TDS from your feed water. When the reverse osmosis system is failing to remove at least 80% of the TDS from the feed water then it is not working as efficiently as it should.
How to calculate the percentage change between feed and product water TDS:
- Feed water TDS Minus Product Water TDS
- Divide the answer above by the Feed Water TDS
- Multiply your answer by 100
If you get less than 80% then optimizing the reverse osmosis system may be as simple as just replacing your filters.
If you don’t really care to do the math. Then for your own piece of mind, keeping an eye on just the product water TDS will help you determine if your RO system is still providing you and your family with clean drinking water or not.
- The ideal TDS concentration for drinking water from ANY reverse osmosis system should be between 0-50 ppm.
15. Replace filters regularly
This is kind of obvious and probably not what you want to hear, but replacing your filters regularly works!
Reverse osmosis filters should be replaced on or before their expiry date, which is usually every 6-12 months, and some RO membranes can last years. However, the lifespan of all the filters really depends on the level of impurities and contaminants in you unfiltered water and how much water you use.
By replacing the filters early, it means the reverse osmosis system will work more efficiently and keep providing you with clean purified water.
16. Look for NSF certification
It’s a good idea to use good quality filters for each stage in your RO system. RO systems are not cheap so make sure you use filters that do what they say the will to keep it running efficiently.
I always look for products that carry the NSF certification.
This means the product has been rigorously tested by an independent American National Standards Institute (ANSI)-accredited testing organization.
It’s not a mandatory test, so not all filters will have it.
But you can be sure that if organizations believe in their product they will take that extra step and have their filter tested to get NSF certified – plus it keeps buyers happy.
Summary
There are many great ways to optimize your reverse osmosis system, but here are our top 16:
| Improvement | Benefits | |
| 1 | Add a pressure gauge | Increases RO efficiency through monitoring and maintaining water pressure at 60 – 80 psi |
| 2 | Use a booster pump | Improves RO performance |
| 3 | Install a whole house sediment filter | Improves RO efficiency and filter lifespan |
| 4 | Install a secondary water tank | Increase flow rate and storage capacity |
| 5 | Drain your storage water tank every 2 weeks | Improves water taste |
| 6 | Clean your storage water tank | Improves taste and stops build up of slime and mold |
| 7 | Install a flush kit | Increases RO membrane lifespan, production rate, and water quality |
| 8 | Add an automatic flush valve | Automatically prolongs RO membrane lifespan |
| 9 | Consider a water softener | Protects RO and extends membrane lifespan from 2-3 years to 5-7 years |
| 10 | Add a carbon post-filter | Removes last impurities from product water improving its quality and taste |
| 11 | Use graded density sediment filters | Captures more sediment, reduces clogging and pressure drop, and increases RO filter lifespans |
| 12 | Replace the carbon filter to protect the membrane | Protects the RO membrane from chlorine damage |
| 13 | Install a flow monitor | Can reduce how often filters need changing |
| 14 | Use a TDS meter | Ensures high TDS rejection rates |
| 15 | Replace filters regularly | Maintains RO efficiency and high contaminant removal |
| 16 | Look for NSF certification | Ensures you are using good quality filters in your RO |
You really don’t have to be a RO expert to make some simple changes or add on a few upgrades yourself. If you do, you’ll definitely notice improved water taste and RO system efficiency and performance.
References
Othman, A., Sohaili, J. and Supian, N.S., 2019. A Review: Methodologies Review of Magnetic Water Treatment As Green Approach of Water Pipeline System. Pertanika Journal of Science & Technology, 27(1).
Pečnik, B., Hočevar, M., Širok, B. and Bizjan, B., 2016. Scale deposit removal by means of ultrasonic cavitation. Wear, 356, pp.45-52.
Shintani, T., Matsuyama, H. and Kurata, N., 2007. Development of a chlorine-resistant polyamide reverse osmosis membrane. Desalination, 207(1-3), pp.340-348.
Nguyen, T.P.N., Jun, B.M. and Kwon, Y.N., 2017. The chlorination mechanism of integrally asymmetric cellulose triacetate (CTA)-based and thin film composite polyamide-based forward osmosis membrane. Journal of Membrane Science, 523, pp.111-121.
Voigt, E., Jaeger, H. and Knorr, D., 2013. Securing safe water supplies: Comparison of applicable technologies (Vol. 1). Academic Press.
