How to Install a Booster Pump on an RO/DI System

How To Install a Booster Pump on an RO/DI System

Note: For this example, we are using the Aquatec 1/4" 8800 Booster Pump Kit. If you are installing a Smart Buddie Booster Pump, see our separate guide on How to Install an Aquatic Life Smart Buddie Booster Pump.

Aquatec 8800 Booster Pump Installation

Tools & Materials

• RO tube cutter or sharp razor blade
• Screws and screwdriver for mounting
• Optional, but helpful:
  • Allen wrench (1/16") for pump pressure adjustment
  • Allen wrench (5/100") for pressure switch adjustment
  • Towel to catch any residual water when cutting RO tubing

Step 1: Mount the Pump

1. Choose a spot near your RO/DI unit and an electrical outlet.
2. Mount vertically with the pump head facing upward for best performance. A flat horizontal surface is acceptable if needed.
3. Secure firmly. The pump weighs about 5 lb and vibrates during use, so use anchors if mounting to drywall.

Note: The pump should be mounted in a dry location.

Step 2: Connect the Pump to the Source Water Line

1. Turn off the water supply.
2. If your system has a manual flush valve, set it to the in-line position.
3. Remove the rubber inserts from the pump’s inlet and outlet by pressing the collar and pulling the inserts out.
4. Locate the red input water line from the water source to the RO/DI unit and cut it cleanly. Have a towel nearby to catch any residual water in the tubing.
5. Push the tube from the water source into the pump inlet and tug lightly to confirm it is secure.
6. Push the tube leading to the RO/DI unit into the pump outlet and tug lightly to confirm it is secure.

Tip: There are indicator arrows on the top of the 8800 Booster Pump indicating which way water should flow through the pump.

Step 3: Install the Pressure Switch (for float valve setups)

1. Find the line running from the RO/DI unit to your reservoir. On Bulk Reef Supply brand RO systems, this line is blue.
2. Cut the blue line at a convenient spot and insert both cut ends into the pressure switch. Direction does not matter for the pressure switch.
3. Wire the switch using the included pigtails: one lead to the pump and the other to the power supply.

Step 4: Leak Test

1. Slowly turn on the water source and let it run for one minute.
2. If your system has a manual flush valve, set it back to the perpendicular position.
3. Check all fittings for leaks. If you see a leak, push the tubing further into the fitting.
4. If leaking continues, shut off water, re-cut the tubing as square as possible, reconnect, and test again.

Example of a good RO tubing cut that will provide a leak-free connection

Example of a bad RO tubing cut that will result in leaks

Step 5: Power On and Set Pressure

1. Never run the pump dry. Ensure water is flowing before plugging in the pump.
2. Plug in the power adapter and let the system run for a minute.
3. Check the RO pressure gauge. The ideal range is 75 to 85 PSI. If pressure is 90 PSI or higher, insert a 1/16" Allen wrench into the adjustment screw on top of the pump and turn counterclockwise slowly until the pressure is within range. You can only adjust the pressure down; this adjustement screw cannot be used to increase pressure.
4. The pressure switch is preset to shut off at 40 PSI. If needed, adjust with a 5/100" Allen wrench. In nearly all setups, adjusting the pressure switch isn't necessary. We only recommend adjusting the pressure switch if absolutely necessary.

Step 6: Verify Automatic Shutoff (if using a float valve or ball valve)

1. Let your RO/DI system fill your reservoir and activate the float valve. If you are using a ball valve, make sure it is installed after the pressure switch and turn it to the off position.
2. Once the ball valve is closed or the float valve is activated, check to make sure there is no more water entering your reservoir.
3. Give the system a few minutes and then check to make sure the pressure switch turns the booster pump off.

Note: The pump will not turn on and off instantly. Depending on the length of tubing from the RO system to the float valve, it may take up to 10 minutes for the pressure switch to trigger.

Tip: Do not use your hand to manually test the float valve as even just a quick release of pressure will restart the pressure-buildup process. This method of testing often leads to unnecessary troubleshooting. If you need to test this quickly, install a 1/4" x 1/4" push connect ball valve after the pressure switch and turn it to the off position.

Alternate Setup Without a Pressure Switch

If you are not using a float or ball valve, You can connect the pump directly to the power adapter. The pump will run continuously while plugged in, so monitor the reservoir to prevent overfilling and unplug it before turning the water off to your RO/DI system to avoid damaging the pump.

Troubleshooting & Common Questions

The Booster Pump Will Not Turn On

Plug another device into the outlet to confirm the outlet is working. Make sure the pump is plugged in and that water is flowing. If you are using a pressure switch, temporarily bypass it and plug the pump directly into the power supply to test.

Low or No Pressure Increase

Check that all tubing is fully seated, lines are not kinked, and that any RO membrane flush valves are in the "closed" (restricted) position. Remember, the adjustment screw only lowers pressure and cannot raise it.

Note: The Aquatec 8800 requires at least 20 PSI of source water pressure. If your supply pressure is below 20 PSI, the pump will not operate correctly.

The Booster Pump Will Not Turn Off

Allow time for pressure to build, as the pressure switch will not activate immediately. Confirm the float or ball valve is closing completely, the pressure switch is installed on the correct line (the product water line after the RO system), and that there are no leaks. In some setups, it may take up to 10 minutes for the switch to activate.

Note: The RO system MUST have a check valve on the product line after the membrane, but before the pressure switch. In Bulk Reef Supply brand RO systems, this is built into the elbow fitting.

Waste Water is Still Flowing When The Pump is Off

If the reservoir is full and the pressure switch has turned off the booster pump but waste water continues to flow from the RO membrane, check that your RO system has a check valve installed on the product line after the membrane and that an Auto Shut Off Valve (ASOV) is in place. Without both the check valve and ASOV, waste water will continue running as long as the source water is on.

The Booster Pump is Noisy

Some noise is normal. Mounting the pump securely instead of resting it loosely on a surface will help reduce vibration.

Pump Feels Hot During Operation

The Aquatec 8800 can feel warm during normal use. If it becomes excessively hot, check that water is flowing properly, the inlet is not blocked, and the pump is not running dry. Prolonged dry operation will damage the pump.

How Do I Add the Aquatec Auto Flush Kit?

Check out this page for more information: Increase RO/DI System Efficiency With a Booster Pump & Auto Flush Valve.