Whether you're setting up your first RO/DI system or need a quick refresher, this guide covers the basic installation steps for a Bulk Reef Supply 4-Stage Value Plus RO/DI System. The video above walks through the entire process if you prefer to follow along visually.

 

How the 4-Stage System Works

Before installation, let's review how water flows through the system:

Stage 1: Sediment Filter - Removes larger particles such as dirt and sand.

Stage 2: Carbon Block - Removes chlorine, odors, and discoloration.

Stage 3: RO Membrane - Filters out up to 99 percent of total dissolved solids (TDS). Wastewater exits through the black tubing.

Stage 4: DI Resin - Polishes the water to zero TDS by removing any remaining contaminants. Output is clean, filtered water from the blue tubing.

 

Installation Options

There are two ways to connect the system to a water source.

Option 1: Black Garden Hose/Utility Sink Adapter (Simplest Setup)

  1. Attach the adapter to your outdoor hose bib, garden hose, or utility sink.
  2. Push the red tubing into the adapter until fully seated.
  3. Place the blue tubing into a clean water container.
  4. Place the black tubing into the sink drain.

Option 2: Chrome Faucet Diverter Valve

  1. Unscrew the aerator from your sink faucet.
  2. Attach the faucet diverter valve, using the included adapter rings if needed.
  3. Unscrew the compression nut and slide it over the red tubing.
  4. Push the tubing over the barbed fitting and tighten the compression nut.
  5. Place the blue tubing into a clean water container.
  6. Place the black tubing into the sink drain.

Tip: To remove tubing from a push-connect fitting, press the retention ring firmly against the fitting and pull the tubing out.

 

Operating the RO/DI System

Once the system is connected, follow these steps:

1) Check for Leaks

  • Turn the flush valve to the parallel position.
  • Turn on the water supply and let the system run for a few minutes.
  • Check all canisters and connections for any leaks.

2) Flush the Membrane Before Use

  • With the flush valve still in the parallel position, let water run for 1 to 2 minutes.

3) Begin Producing RO/DI Water

  • Turn the flush valve to the perpendicular position.
  • The system will now begin producing clean water from the blue line and discharging waste from the black line.

4) Flush the Membrane After Use

  • Turn the valve back to the parallel position.
  • Flush for 1 to 2 minutes.

5) Shut off the System

  • Turn off the water supply.
  • Leave the flush valve in the parallel position for storage.

 

Helpful Reminders

  • Always use a timer when producing water. Overflow accidents can lead to water damage. If you are permanently installing your RO/DI system near a larger storage container, consider adding a Float Valve to provide some extra protection from overfilling.
  • Flush your system regularly to keep your RO membrane in good condition.
  • Monitor your system using an inline TDS meter and pressure gauge, if equipped.

 

Downloadable Instructions: BRS 4-Stage RO/DI Instructions

If you have any other questions or need further help, contact our reefing experts at 763-432-9691

 

 

RO/DI Frequently Asked Questions

Q: Is it normal for the DI stage to not fill completely with water?

A: Yes, air gets trapped in the top of the canister and has no way to escape. This does not interfere with system performance, but if desired open the canister slightly while the unit is running to allow the air to escape. Re-tighten the canister when the water reaches the top.

Q: Is it normal for TDS to be higher when the system is first turned on?

A: Yes, this is called “TDS creep” and is normal on all RO systems. Allow the RO system to run for 10 minutes before testing TDS.

Q: Is it okay to leave water in the canisters between uses?

A: Yes, it is advised to keep them wet between uses, and store in a cool, dark location away from environmental extremes. Exposure to sunlight or freezing can cause damage to the filters and canisters and should be avoided.

Q: How often should I use the flush kit?

A: We suggest flushing the membrane for a few minutes before and after use. There is an auto flush kit available for a more automated solution.

Q: My pressure gauge reads less than 50 psi. Do I need a booster pump?

A: The membrane will not perform “optimally” below recommended pressure, but the reduced performance may not be substantial enough to warrant a booster pump. As it approaches 35 psi the performance drop will become significant and you will likely want to purchase a booster pump.

Q: What is a normal TDS reading?

A: TDS from most tap water will be in the 100-300 range but many sources can be well over 500. Normal product water from RO membrane will be around 98% of tap water’s TDS under optimal conditions. Tap water with a TDS of 300 should be around six coming out of the membrane. Product water emitted from the DI resin canister should be zero. Operate the system for ten minutes prior to testing for TDS, readings will always be higher when the system is turned on initially.

Q: My DI resin seems to be depleting quickly, what’s wrong?

A: Usable lifespan of the DI resin cartridge will vary widely. Feeding the resin from the RO membrane with one TDS will have approximately five times the usable life as feeding it with five TDS. Outside of that, carbon dioxide in your water supply or a poorly performing RO membrane are the biggest causes of early DI exhaustion.

Q: I know I have good pressure, but all of the water is rushing down the drain and I’m barely getting any product water; what’s going on?

A: It’s not uncommon to accidentally leave the flush valve in the open/flush position. For normal water production, the valve should be the perpendicular position. Only during membrane flush should the valve be parallel with the line.

Q: My system doesn’t seem to be making a lot of water, what’s wrong?

A: Keep in mind that 75 GPD is approximately three gallons an hour. The flow will be slow and close to a constant trickle. If it is slower than that, it’s almost always because the flush kit is open or the home’s water pressure is low and there is insufficient pressure feeding the membrane.

Q: Can I reduce the amount of waste water my system produces?

A: The waste water is a critical component of a properly functioning RO system. The best way to reduce the volume of waste water to product water ratio is to install a second membrane in series which will effectively cut this ratio in half. We call this a "Water Saver Upgrade."