What is GPD in Reverse Osmosis?

GPD stands for flow rate of water measured in Gallons per Day. Reverse Osmosis is a method of purifying water by forcing it through a semi-permeable membrane. The membrane allows only water molecules to pass through but not any contaminants.

The higher the GPD, the more water can be purified in one day. 

For example, a reverse osmosis system with a GPD of 10 will purify 10 gallons of water in one day. A system with a GPD of 0.5 will purify half a gallon of water in a day.

Suppose you have 100 gallons of dirty water that needs to be purified and it takes 4 days to complete the process, what would be the GPD?

GPD = 100/4 = 25 Gallons per Day

Is Higher GPD Membrane Better?

The answer is YES, higher GPD membrane is better. A higher GPD membrane will purify more water in a given time period. The reverse osmosis system with a GPD of 10 will purify 10 gallons of water in a day. The one with a GPD of 0.5 will purify half gallon of water in the same time period, which means the first one can purify twice as much water as the second one in the same time period.

Is Higher GPD Membrane More Costly?

The answer is NO, it actually costs less to buy a system with high GPD membrane because you don’t have to buy another reverse osmosis system once your capacity requirement increases or when you want to purify more water in a given time period. You can simply upgrade to a system with higher GPD membrane or use the existing one for longer time period without the need to replace it.

What is the GPD of a Typical RO Membrane?

The GPD of a typical RO membrane is between 1 and 3. If your reverse osmosis system has a GPD of 2, it means that it will purify 2 gallons of water in one day.

How much water does a RO system use a day (in GPD)?

As we mentioned above, it depends on what GPD your RP membrane is rated for. A reverse osmosis system with a GPD of 2 will consume 2 gallons of water per day. A system with a GPD of 3 will consume 3 gallons of water per day.

How Many Gallons of Water Does It Take to Make a Gallon of RO Water?

The answer to this question is simple, it takes 1 gallon of water to produce 1 gallon of purified water. For example, a system with a GPD of 2 will produce 2 gallons of purified water in one day.

What Is the Best GPD for a Home RO System?

The answer to this question ultimately depends on your needs and the quality of water that you want to filter. The higher the GPD, the more expensive it will be. The higher the GPD, the less time it will take to produce 1 gallon of purified water. The lower the GPD, the better tasting your water will be.

How do I Calculate my RO System’s GPD?

You can quickly calculate your reverse osmosis system’s GPD by using the following equation:

GPD = Gallons of Water Produced / Number of Days

For example, if your reverse osmosis system produces 2 gallons of water in an day, then it has a GPD of 2.

How Much Water Does a RO System Use a Day?

The answer to this question depends on the size of the system and the GPD. For example, a reverse osmosis system with a GPD of 2 will consume 2 gallons of water per day.

What Is the Difference Between 50 GPD and 75 GPD?

A 50 GPD rated RO membrane is capable of producing (filtering) upto 50 gallons of water per day. On the other hand, a 75 GPD RO System will produce upto 75 gallons of water every day.

What is the difference between a 75 GPD and a 50 GPD Reverse Osmosis System?
Meet the author: Paul White

Paul is water engineer by trade and is very passionate about innovative solutions for water filtration. His goal is to make drinking water accessible and affordable to all. An avid runner, he is currently training for a marathon. “Running is my sanity. Writing is how I organize my thoughts. I’m a poet and writer who is passionate about change. I aspire to be the best version of myself, and to help others do the same.” Learn more about Paul and the rest of the team.