How Long Does It Take To Fill Up A Reverse Osmosis Tank?

You have probably seen one of these futuristic-looking systems planted somewhere, and were amazed by it and decided to go on ahead and buy it. But, you need to know the proper functioning and working of these water systems before you can go out and purchase one.

Even if you have already bought one, we don’t blame you, these are really cool-looking devices, and who wouldn’t want one in their home? But don’t worry, we will teach you all you need to know and answer questions such as “How long does it take to fill a Reverse Osmosis Tank?” and other related questions.

So, let’s dive straight in and find out what the hype about this technology is!

How Long Does It Take To Fill Up A Reverse Osmosis Tank?

How long does it take to fill a Reverse Osmosis Storage Tank?

To start off, this isn’t a very black-and-white answer. That goes to say there are a few things that need to be considered before answering this question. One needs to have in-depth knowledge about the reverse osmosis system, but even if you don’t that’s alright, we got you covered.

Related Topic: What does Reverse Osmosis Water Taste Like?

To give you an idea, it takes about two to four hours to fill up a 2.8-gallon reverse osmosis water tank. Let’s talk about the factors that affect the functioning of the reverse osmosis water tank.

pressure of water should be between 60 PSI to 80 PSI

They are as follows:

Water Pressure:

The perfect amount of water that needs to be given to a reverse osmosis water tank is 60 pounds per square inch (PSI). To ensure smooth operation, the recommended pressure of water should be between 60 PSI to 80 PSI. The water system can work on 40 PSI too, so that’s not much of an issue.

If you find out that the pressure of water exceeds 80 PSI, then you should get a regulator which is made for these reverse osmosis tanks. On the other hand, if the pressure is lesser than 60 PSI, then get an assist pump which will bring the pressure up and boost the process.

Related Article: Reverse Osmosis Problems and its Solutions

The Kind of Reverse Osmosis System:

There are many different options out there for you to choose from, the capacity of the tanks ranges from 50, 75 to 100 gallons of filtered clean drinking water per day.

It is pretty obvious that the 100-gallon tank will fill the fastest because the system in it is capable of rapidly filtering water as compared to the other water capacity tanks.

Despite having more clean water with the 100-gallon tank, the amount of water that can be stored in the tank would remain the same. So, in order for you to make the most of the filtered water, you would have to consume more in order for the tank to keep filling the storage up.

The Temperature of the Water:

These systems are built to withstand efficiency drops due to water, but if the water temperature drops to below 40 degrees Fahrenheit, this will definitely affect the efficiency of your filtering system.

The efficiency drops to 50% if the temperature of the water being fed into the system comes closer to the freezing point of water. That is 32 degrees Fahrenheit.

The Filter and the Membrane:

It is pretty obvious that a new filter will have the maximum capacity to filter water, compared to those filters that have been in use for over a year. That is because very little debris that is filtered out from the water, hinders the osmosis membrane from functioning at peak capability.

So, that means that osmosis filters that have been in use for a while are going to take longer to fill the tank, but the good thing is, the quality and standard of water don’t drop, but the rate at which water is filtered every hour, is.

Related Topic: Best Reverse Osmosis for Well Water

Why won’t my Reverse Osmosis Water Tank fill completely?

Don’t worry if your Reverse Osmosis tank isn’t filling up. We are going to list down the problems and the trouble-shooting that goes along with it below:

The Valves:

There is a possibility that the valve that is connected to the cold supply of your sink is closed, and the valve of the osmosis tank is closed. Make sure they are both open and pointing in the direction of the open side.

The leak detector valve:

There is an in-built mechanism where the leak detector will cut the water supply to the osmosis system when the valve comes in contact with water. Check if the valve has cut off the water supply and turned the water supply off.

The Air Pressure in the Tank:

There is a possibility that the pressure of the air inside the air-charged water tank is too much, and that hinders the tank from filling to its full capacity.

How Long Does It Take To Fill Up A Reverse Osmosis Tank?

Clogged Osmosis filters:

The storage tank can also stop filling up to its full capacity because of clogged osmosis filters.

Clogged Osmosis Membrane:

The little and hard minerals can often get stuck in the membrane and form stoppages and barriers that prevent water from flowing freely, and that can also be a cause for the water tank to not fill to the brim.

Kinked Tubing:

How Long Does It Take To Fill Up A Reverse Osmosis Tank?

A kink, or as they say a twist in the tubing can cause the water flow to become restricted and clogged, this stoppage can cause the water tank to not fill up to its full capacity.

More water output than production:

It is a possibility that the amount of water being consumed and used is much more than the amount of water filtered and produced by the osmosis system, this can be dealt with by buying a bigger per-gallon osmosis water tank.

How long does it take to fill a 9 Gallon Reverse Osmosis Water Tank?

The average time for a Reverse Osmosis tank of about 2.8 gallons takes about 4-8 hours, which is about 10.6 liters of filtered and clean water. So, according to this time frame, filling a 9-gallon water tank would take roughly about 8-12 hours to fill completely.

Related Article: How to clean Reverse Osmosis System

Why is my Reverse Osmosis Water tank not filling up?

There can be quite a number of reasons that your Reverse Osmosis Water Tank is not filling up, and troubleshooting them can be as simple as flipping over a valve.

The possible problems can vary from closed valves, which can be flipped over to open them. To a leak detector valve which is built for the safety of your Water Tank, to the air pressure in the tank, which can be a cause for concern.

There can be clogged filters, and a clogged osmosis membrane as well. Even a kink or a twist in the tubes or pipes can cause this problem.

This may seem like a lot to take in, but it is quite easy to troubleshoot. We have listed down all the possible problems and their solutions above, so go on and give that a read to solve your problem.

Related Article: Where to buy Reverse Osmosis Water System

How to know if Reverse Osmosis Tank is closed?

This is fairly easy, all you have to do is, you have to inspect the tank and determine whether it is full of water or not. If the tank is full of water, you have to open the faucet and then inspect the flow of water. Continue inspecting the flow rate for a minute.

 If you notice that you have turned on the faucet and nothing is flowing, inspect the valves and check whether they are in an open or closed position.

If the valve is closed, flip it in the opposite direction and open it. If you have done everything, it is now time to inspect the air pressure in the tank, you can do so by using a tire pressure gauge, and you will find out the air pressure inside the tank. The pressure should be around 5-7 PSI.

How Long Does It Take To Fill Up A Reverse Osmosis Tank?

Conclusion | How Long Does It Take To Fill Up A Reverse Osmosis Tank

As we all know water is a very precious commodity, and it is running scarce day by day. Water is essential to life, and every day the groundwater level reduces. If there comes a day there is no water left to drink, humanity will come to an end, despite the earth being 71% water.

Clean and drinking water is a blessing, and it is very necessary to not let any of it go to waste. These Reverse Osmosis Water tanks are a great invention that recycles water and makes it clean and fit for drinking.

It is urged for everyone to get them, not because they are cool and futuristic looking, but because it is necessary for a sustainable future.

See Also: Best Countertop Reverse Osmosis System

The upkeep and maintenance of these tanks and systems are fairly easy, and you can find tons of guides and helpful videos online if need be, but we hope we were able to help you in finding out the problems and the various troubleshooting methods we listed in this article. Here’s to a future with safe and clean drinking water!


This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

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