Reverse Osmosis Tank Not Filling?


How Long Does it Take to Fill a Reverse Osmosis Storage Tank?

reverse osmosis storage tankIf your Reverse Osmosis water tank isn't filling, and you're wondering how long it normally takes to fill an RO tank, the short answer is it typically takes 2 to 4 hours to fill a standard reverse osmosis holding tank (2.8 gallons or 10.6 L).

Because the reverse osmosis filtering process takes time, storage tanks are a necessary component with any RO system. Without an RO holding tank, you would have to wait 5-10 minutes just to fill a glass of water. With an RO storage tank, you can quickly fill your glass, pot, or water bottle.

Reverse Osmosis Tank Not Filling Up?

  1. System Flow Rate: The type of RO system you have will impact how quickly water will fill your water storage tank. For example, the Watts Kiwk Change RO System is designed to produce 100 gallons of water per day. The Hydro Guard Reverse Osmosis Systemsediment filters produces 50 gallons of water per day. This means that the 100 GPD system will replenish the water storage tank twice as fast a 50 GPD system. If you suspect your system is not producing at capacity, Below we provide steps to determine how much water your RO system is actually producing in a 24-hour period.
  2. City Water Pressure: The ideal water pressure for most RO system to operate efficiently is 60 psi, but should operate properly between 40 and 80 psi. When your household water pressure is low (near or below 40 psi), water cannot be pushed through the RO membranes to produce filtered water. You may need to add a booster pump to your RO system to increase the incoming water pressure to the RO system.
  3. Filters Need Replacements: Generally speaking, RO water filters should be replaced every 12 months and the reverse osmosis membrane every 24 months. When filters can no longer absorb contaminants and become fouled or clogged, the flow rate on your reverse osmosis system can slow to just a trickle. Clogged filters are often the main culprit when an RO tank is filling slowly. Check out more details: Why You May Have Slow Flow Rates From Your RO System.
  4. Tank Pressure: The tank pressure should be at 5-7 psi when empty. If the tank bladder is ruptured or damaged, then you will need to replace the tank. More tips available in our RO Troubleshooting Guide.reverse-osmosis-drinking-water-for-family

Why is my Reverse Osmosis System Making Noise? 

Once you've figured out the issue and your storage tank is filling up again with filtered water, you may hear noise. That noise below the sink simply indicates the system is now producing more water and refilling the storage tank.

If you have an air gap faucet with your RO system, be aware that a little noise is common with "air-gap" faucets. The "gurgling" noises  are usually made as the contaminated water goes to the drain line. 

If you ever hear "hissing" noises, you should immediately call your local water treatment professional as there may be a problem with water pressure, the air gap faucet, or a leak. More tips available in our RO Troubleshooting Guide.

>>Learn more about how RO filtration works

How to Determine Water Flow Rate of Your Reverse Osmosis System

Step 1: Make sure the incoming water line to the RO system is turned "ON" and turn the ball valve on top of the reverse osmosis storage tank to the "OFF" position (generally a 1/4 of a turn).

Step 2: On your reverse osmosis faucet, flip the handle to the "up" position, so the faucet is now locked into a continually open/flow position. At this time any water in the lines will drain.

Step 3: After there is no more water in the system lines, wait about 5 minutes to make sure all water has drained.  (NOTE: If you get no flow from the reverse osmosis faucet, the system is not producing water).

This flow rate represents the flow rate the system is producing water and the rate that the reverse osmosis storage tank would be filling if the valve on the reverse osmosis pressure tank was in the "open" position.

Step 4: Once you have a continual drip or slow flow from the faucet, using a measuring cup, measure how much water drips/flows from the reverse osmosis faucet into the measuring cup for 60 seconds.

Step 5: Now it's time to do the math!

    • Take the number of ounces your RO system produced in one minute.
    • Multiple this number by 1440, which is the number of minutes in a day.
    • Divide this number by 128 which is the number of ounces in a gallon.

This number is the amount of water your RO system is producing over a 24 hour period.

If you want an hourly water production rate, simply divide the number by 24.

Example: Within 1 minute your system is produces 4 ounces per minute. 4 x 1440 (minutes in day)= 5760 (ounces) divide by 128 (ounces in a gallon)= 45 gallons per day. Divide by 24 (hours in day) = 1.875 gallons per hour

Replacement Reverse Osmosis Tanks