5 Causes of Reverse Osmosis Low Water Pressure (2024)

Your RO system might experience low water pressure for multiple reasons ranging from clogged filters and membrane to air pressure in the tank.

Some of the most frequent causes, however, are low pressure inside a full tank, a faulty water supply line valve, and low water pressure from the city water line. Sometimes, the issue can even be a ruptured bladder tank.

Here’s a breakdown of the most common reasons for low water pressure in a reverse osmosis system:

  • Clogged filters or Membrane
  • Ruptured bladder tank
  • Problem in water supply lines
  • Low air pressure inside tank
  • Fluctuating water pressure

1. Clogged RO Filters Or Membrane Can Cause Low Water Pressure

If you have a slow water flow rate in your RO system, the most likely issue will be the filters or the membrane. Over time, they tend to get clogged up.

This is due to the fact that reverse osmosis filters continuously separate harmful contaminants, microscopic dirt particles, and other impurities from the water supply. When all this builds up, it can restrict the regular water flow.

You can avoid this problem by changing your filters at least once a year. If the water in your area is particularly impure, it’s a good idea to change your RO filters every six months.

5 Causes of Reverse Osmosis Low Water Pressure (1)

The same goes for your reverse osmosis membrane. This membrane should be replaced every three years. The time frame yet again largely depends on the water condition but also the model of your RO system.

When the membrane gets clogged, your RO system will take a lot longer to produce clean drinking water.

If you have difficulty replacing this part on your own, you can also reach out to your local technician to guide you through the process.

2. Ruptured Bladder Tank Can Cause Slow Water Flow

There are multiple reasons that can cause the holding tank bladder of an RO system to rupture. However, in most cases, it’s due to a lack of regular maintenance.

5 Causes of Reverse Osmosis Low Water Pressure (2)

Detecting a ruptured tank is pretty straightforward. Simply check if the water flow rate decreases after providing one cup or 8 oz of water.
If you establish that your RO tank is ruptured, you will need to consult with an expert and replace the entire storage tank with a new one.

3. Problem in Water Supply Lines

If you have a twisted or crimped water line somewhere in your RO system, the water flow will become slower.

5 Causes of Reverse Osmosis Low Water Pressure (3)

To determine whether this is the reason for your low water pressure, check the water supply lines in your RO system and see if the hoses are properly connected. If you come across a twisted hose, simply straighten it by hand.

While you’re at it, you should also inspect the water supply valve and make sure it’s open all the way.

4. Air Pressure Inside the RO tank Is Low

Inside your RO system, there’s a pressurized tank that needs to maintain a certain amount of air pressure in order to provide optimal water flow. If this pressure drops, you’ll have a slower water flow.

5 Causes of Reverse Osmosis Low Water Pressure (4)

The pressure inside a 24-gallon tank should be 6 to 8 PSI (pounds per square inch) when empty. Thankfully, checking the air pressure inside the tank is quite straightforward. Check the Schrader valve that is placed under a blue color cap on the side of the water tank. This means checking that it’s connected properly and that it’s tight enough.

After doing this, you should also check the pressure with a pressure gauge. To do this, simply empty the water from the tank and measure the pressure with the gauge.

If the air pressure is lower than what it’s supposed to be, use an air pump and keep pumping air inside the tank. Take extra care when doing this, as extra pressure (> 8 psi) might damage the RO tank.

5. Fluctuating Water Pressure

A reverse osmosis system requires around 30-40 PSI of normal water pressure in order to operate, and 60 PSI to maintain optimal water flow.

5 Causes of Reverse Osmosis Low Water Pressure (5)

Occasionally, the water pressure in your system might fluctuate temporarily due to inconveniences such as maintenance work or local water supply issues. The best course of action is to wait it out and see if the pressure goes back to normal after a day or two.

However, if the low water pressure issue persists, you should contact your local utility company and ask for guidance.

The Importance of Pressure in RO Systems

RO tanks contain two different compartments for air and water. Both compartments have to maintain a standard pressure to function properly.

The air that is pressurized inside the air compartment pushes water through the faucet. In order for this operation to be executed, the storage tank pressure has to be between 6 to 8 PSI when it’s empty.

Once water fills up, the tank pressure increases. The increased pressure is released when water flows through the faucet. For a tank full of water, the tank pressure should be at 30 PSI.

Most RO units feature a shut-off valve that stops the water production if the pressure in the tank exceeds the water pressure value. For optimal water pressure, your system’s pressure should be between 25 PSI and 70 PSI.

How to Increase or Maintain Pressure in an RO System

To increase the water pressure in your RO system, clean the filters regularly and replace the membrane annually. All of this falls under general maintenance and might seem like a no-brainer, but many tend to overlook it.

If the problem persists, look for a ruptured tank bladder, monitor the incoming water line, and maintain the optimal water and air pressure inside the storage tank.

If all else fails, you might have to install a sediment filter, add a flush kit, or get a new secondary water tank.

1. Regular Maintenance

Regular maintenance can prevent most of the common issues with your reverse osmosis system, including low water pressure.

By changing your RO filters and membrane in a timely manner and inspecting them on a weekly basis, you’ll prevent the build-up of dirt and contaminants. Additionally, it’s also a good idea to examine the storage tank, drain tube, feed water valve, and drain line regularly.

Make use of a PSI gauge or the valve under the blue cap of your system to keep the water and air pressure in check.

Consult an expert if you detect any leaks that disrupt the water flow.

2. Use an Electric Booster Pump

One of the easiest ways to improve the pressure and performance of your reverse osmosis system is by adding a booster pump.

This will increase the treated water production rate, boost the storage volume of the pressure tank, and improve the water flow rate that flows through the faucet.

However, do note that the feed pressure might increase up to 100 PSI with a booster pump, which is neither good nor bad (depends on you). There’s a screw on the pump to adjust the pressure to keep it at the desired levels at all times.

3. Install a Sediment Filter

If your RO filters get clogged frequently, whole-house sediment filters are a great option to consider.

Sediment filters are made of strong metal, which makes them very durable. They can increase your RO water pressure by:

  • Improving the longevity of the filters;
  • Bring clogging down to a minimum;
  • Reducing the wear and tear on the system;
  • Increasing the efficiency of the water filters.

4. Get a Secondary Water Tank

Installing a secondary water tank will improve the flow rate of the faucets. It basically doubles the capacity for pressure delivery.

Secondary tanks are available in compact sizes and can be installed under the faucet or inside a cupboard. Moreover, the installation process is very easy, so you won’t have to hire a professional.

Conclusion

The first course of action when you are experiencing water pressure problems with your RO system is to find out where the problem lies. Go through all of the possible causes one by one until you zero in on the problem.

Once you find out what you are dealing with, take adequate action. Remember that you can always consult a professional at any stage of the process.

If the water pressure doesn’t improve after troubleshooting then it may be time to get a new reverse osmosis system. Refer to our ro water filter review article for top recommendations.

5 Causes of Reverse Osmosis Low Water Pressure (2024)

FAQs

5 Causes of Reverse Osmosis Low Water Pressure? ›

Your RO system might experience low water pressure for multiple reasons ranging from clogged filters and membrane to air pressure in the tank. Some of the most frequent causes, however, are low pressure inside a full tank, a faulty water supply line valve, and low water pressure from the city water line.

What causes low water pressure in reverse osmosis system? ›

Your RO system might experience low water pressure for multiple reasons ranging from clogged filters and membrane to air pressure in the tank. Some of the most frequent causes, however, are low pressure inside a full tank, a faulty water supply line valve, and low water pressure from the city water line.

How do you fix low pressure on a RO system? ›

Insufficient Air Pressure in the RO Tank

You can use an air pressure gauge to check the tank air pressure. If the pressure is too low, add enough air using a pump to bring it up to 8 psi. Just be sure to add a little air at a time to avoid rupturing the air bladder.

How do I increase the water pressure in my reverse osmosis system? ›

Simply mount the booster pump between the water supply and the RO. A high pressure switch will mount on the pressurized storage tank tubing. This pressure switch cuts off power to the pump when the water storage tank reaches 40 PSI (or rated pre set pressure of the switch).

What is a major problem with reverse osmosis? ›

One of the biggest disadvantages to reverse osmosis water systems is wasted water. Studies show various reverse osmosis systems can waste between 3 and 20 times as much water as they produce.

What can cause the water pressure to be low? ›

The short answer is low water pressure in your home arises due to a number of causes. Some include a shut or blocked water meter valve, mineral buildup clogs pipes, corroded pipes, or even a crack in the main city supply pipe to your home.

What PSI should reverse osmosis be? ›

The ideal pressure for operating an RO system is 60 PSI. Pressure below 40 PSI is generally considered insufficient, and should be boosted using a pressure booster pump.

Can I add air to a full RO tank? ›

If your reverse osmosis tank has lost its pressure, you can easily add pressure back to the tank with a bicycle pump. The air valve on an RO tank is called a Schroeder valve, and its the same valve you'll find on your bicycle tire.

What affects osmosis pressure? ›

Osmotic pressure can be calculated with the van 't Hoff equation, which states that osmotic pressure depends on the number of solute particles, temperature, and how well a solute particle can move across a membrane. Its measured osmolality can describe the osmotic pressure of a solution.

How do I get more water pressure back? ›

A quick and easy way to increase water pressure is to adjust the pressure-reducing valve, which can be found in your home, usually close to your water meter. If your pressure gauge reading was low, make slight adjustments to your regulator.

How do I know if my RO membrane is clogged? ›

The number one indicator is when the RO system simply stops producing water or the flow of the RO water is weaker than it used to be. Next, if your RO system is running constantly that is another sign that it is time to replace your membrane.

Why can't you drink reverse osmosis water? ›

According to the World Health Organization, low mineral (TDS) drinking water produced by reverse osmosis or distillation is not suitable for long term human consumption and in fact, can create negative health effects to those consuming it. This lack of minerals may also impact the taste negatively for many people.

How can I tell if my reverse osmosis system is working? ›

Check the tank to see if it's full of water or not. If it's full, open the faucet and check the flow rate. If nothing is flowing, check to make sure the valve is in the open position (handle in line with the tubing). If everything looks right, check to see if any pressure is in the tank with a tire pressure gauge.

Who is responsible for low water pressure in my house? ›

You are responsible for installing and maintaining the water pipes within the boundaries of your property. This includes water pipes inside your home as well as drainage and supply pipes outside your home, within your property boundary.

Can you improve low water pressure? ›

Low water pressure can turn simple tasks into hassles, but once you identify the cause, either the necessary plumbing fix or a water booster pump can drastically improve your water pressure.

What can affect water pressure? ›

Factors that Affect Home Water Pressure
  • Hard Water. The high mineral content in hard water produces limescale, which builds up and can clog showerheads, pipes, and taps, reducing the water pressure. ...
  • Time of Day. ...
  • Water Heater Damage. ...
  • Showerhead. ...
  • Leaks. ...
  • Clogged Pipes. ...
  • Re-Circ Pump Issues.
May 22, 2020

How much pressure should a 4 gallon reverse osmosis tank have? ›

The optimum pressure for a 2-4-gallon reverse osmosis tank is 6-8 PSI.

What is standard recommended water pressure for RO water purifier? ›

RO water purifiers normally need a pressure of between 5-40 PSI (pounds per square inch) for them to work effectively.

How often should you drain your RO tank? ›

Ideally, you should completely drain your RO storage tank about every 2 weeks. Draining your tank ensures that the water will remain fresh, as well as helping the reverse osmosis membrane maintain the pressure it needs to flush out impurities.

Do you need a booster pump for RO system? ›

Do I need a reverse osmosis booster pump? If your water pressure is below 40 psi, you need a booster pump for your RO system to function properly. You should also consider getting a booster pump if your water pressure hovers between 40 and 50 psi or if TDS levels in your water are over 500 ppm.

Do you need to add anything to RO water? ›

Ways You Can Remineralize RO Water

Add sea salt that is rich in minerals at the rate of one small pinch per glass of water or 0.25 teaspoons per gallon. It has to be a fine salt, such as Himalayan sea salt that is effective and won't give a salty taste.

What happens if osmotic pressure is low? ›

Low osmotic pressure means that a solution does not have enough solute in it to make water want to flow into it to reduce its concentration. Water flows by osmosis from areas of low solute concentration to areas of high solute concentration, creating hydrostatic balance.

What are the three factors that affect osmosis? ›

Osmosis rate is affected by a number of variables, including temperature, membrane permeability, and the gradient of solute concentration. Osmosis has several useful uses, including water desalination and purification, food preservation, and the preservation of biological materials.

What pressure stops osmosis? ›

Osmotic equilibrium and osmotic pressure

One way to stop osmosis is to raise the hydrostatic pressure on the solution side of the membrane. This pressure squeezes the solvent molecules closer together, raising their escaping tendency from the phase.

Is 70 psi too high for water pressure? ›

How High Is Too High? The ideal water pressure level is between 50-70 PSI. If your water pressure goes above 70 PSI (even occasionally), you should install a pressure regulator to your main water line.

Do reverse osmosis systems need maintenance? ›

Most of the filters on your system need to be replaced at least every 3-12 months. Depending on the system, you can have anywhere from 3-5 filters. Additionally, you should sanitize your RO system at least once a year. Therefore, we recommend that you do reverse osmosis system service at least annually.

What damages RO membrane? ›

Silt, Mud, Sand and Algae: Suspended matter like silt, mud and algae can cause considerable damage to RO membranes. They also decrease system performance and increase maintenance requirement.

How long should an RO system last? ›

How long do RO systems last? They could last 10-15 years but only when they are regularly maintained. This means the cartridges should be replaced annually and the parts are regularly inspected for any problems. Some parts may wear out (e.g. storage tanks, tubing) through time.

Is RO water bad for kidneys? ›

RO water has a lower pH and is thus acidic. Drinking acidic water for a long period of time can adversely affect your health by increasing your risk of gastrointestinal issues and kidney disorders.

Is RO water hard on kidneys? ›

Reverse osmosis systems stand as some of the most reliable options when it comes to water filtration. If you're healthy, fit and have a rich diet, the lack of minerals in RO water will have no effect on your kidney whatsoever.

What is the healthiest water to drink? ›

Mineral, structured, and pure spring water are some of the healthiest water you can drink because they're clean and contain all the essential minerals your body needs. Filtered water removes contaminants but might also remove essential minerals.

What happens when osmotic pressure is too low? ›

(b) When cells are placed in distilled water whose osmotic pressure is less than that of the intracellular fluid, the rate of flow of water into the cells is greater than the rate of flow out of the cells. The cells swell and eventually burst.

How do I know if my RO tank is bad? ›

Here are the five most common tell-tale signs that your RO tank bladder is ruptured:
  1. Reduced Water Pressure. ...
  2. Foul or Salty Tasting Water. ...
  3. Water Leaking From The Bottom of The Tank. ...
  4. Excess Air in the RO System. ...
  5. Slow-Moving or Stagnant Water.
Jul 19, 2022

What are the factors affecting osmosis pressure? ›

The factors affecting the osmotic pressure are - Solute concentration and temperature. Solute concentration is the number of solute particles in a unit volume of the solution that directly determines its potential osmotic pressure. Osmotic pressure increases with the increase in temperature.

How do you increase osmotic pressure? ›

Increasing the osmotic pressure of a food through drying or by the addition of sugars or salts leads to the reduction of water available to the bacterial cell. The major reaction toward an osmotic upshift is the efflux of water from the microorganisms into the external environment.

Does water go from high to low osmotic pressure? ›

Water moves from a region of low osmotic pressure to a region of high osmotic pressure.

What will happen if the blood osmotic pressure is not maintained at normal level? ›

If it is not maintained, the cell may gain or lose the water and get destroyed. For example, RBC will gain water when osmotic pressure is high and burst and get destroyed and resulting in death.

Why is pressure important for reverse osmosis? ›

Reverse osmosis filtration uses high pressure (100–800 psi) to force water through a semi-permeable membrane that filters out dissolved ions, molecules, and solids (nanofiltration). This process can both remove microbiologic contamination and desalinate water.

How does pressure affect reverse osmosis? ›

Low water pressure will result in reduced production and premature fouling of the membrane. The ideal pressure for operating an RO system is 60 PSI. Pressure below 40 PSI is generally considered insufficient, and should be boosted using a pressure booster pump.

How many years does a RO system last? ›

How long do RO systems last? They could last 10-15 years but only when they are regularly maintained. This means the cartridges should be replaced annually and the parts are regularly inspected for any problems. Some parts may wear out (e.g. storage tanks, tubing) through time.

What is the life expectancy of a reverse osmosis tank? ›

A well-maintained reverse osmosis system can run efficiently for 10 to 15 years, providing you with clean, safe drinking water throughout its lifespan. However, it is imperative to replace each of its filters and the RO membrane as prescribed by the manufacturers.

What is the average life of RO? ›

~ RO Membranes typically last approximately 2-3 years, although we've seen them last up to 5 years. If you have really hard water or if you never cleanse the membrane, your RO membrane may perish sooner.

What 2 factors must be in place for osmosis to occur? ›

Therefore, for osmosis to occur, the membrane must be permeable to water, but impermeable to the solute, and the concentration of the solute must be different on the two sides of the membrane.

Does pH affect osmosis? ›

The pH of a solution plays an important role in osmotic pressure and therefore influences the effectiveness of a draw solution as flux enhancer.

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