Why Am I Not Getting Enough Water Out of My RODI System?

Reverse osmosis deionization (RODI) systems are widely used for producing purified water for residential, commercial, and professional applications. Despite their effectiveness, many users face a common issue: insufficient water flow or low production. If you’re wondering why your RODI system isn’t giving you enough water, there are several factors to consider, ranging from water pressure to resin maintenance. In this guide, we’ll explore these issues in detail and provide practical solutions.

Understanding Water Pressure and RO Performance

One of the primary factors affecting RO water production is the incoming water pressure. RO membranes require a minimum pressure to function efficiently.

• Minimum Water Pressure: For most RO systems, you need at least 60 psi of water pressure entering the system. If the pressure is below this level, the RO membrane cannot push water through effectively, resulting in slow flow rates.

• Booster Pumps: If your water pressure is low—say 45 psi from well water—you can use a booster pump to increase it. Booster pumps typically add around 40 psi, bringing your system up to 75–80 psi, which is ideal for optimal RO performance.

Choosing the Right Booster Pump

When selecting a booster pump for your RO system, there are two main types to consider: impeller pumps and positive displacement pumps.

Impeller Pumps

Impeller pumps are the most popular choice for residential and professional RO systems. They create pressure without forcing all water through the membrane at once. Key benefits include:

• Reliability: Provides consistent pressure boost without overloading the RO membrane.

• Efficiency: Supplies water as needed by the system, reducing waste.

• Applications: Useful for tall buildings or multi-story cleaning, as water pressure requirements increase with height. For example, every 10 feet of pole height requires 4.5 psi to maintain flow, so a booster pump ensures sufficient pressure for high-reach systems like Gardiner poles reaching up to 90 feet.

Positive Displacement Pumps

Positive displacement pumps force all pumped water to go somewhere, which can be less forgiving for standard RO setups. While they may be effective for specialized applications, impeller pumps are generally more suitable for residential and commercial RODI systems.

Tip: Booster pumps start at around $125 and are a cost-effective solution for low water pressure issues.

Total Dissolved Solids (TDS) Issues and DI Resin

Another common issue with RO systems is a rise in Total Dissolved Solids (TDS), especially if you don’t have a DI (deionization) resin cartridge. TDS measures the concentration of dissolved ions in water, and a rising TDS indicates that the water is not being fully purified.

Why Your TDS May Rise

• Incomplete Resin Use: In DI cartridges, water does not always contact all resin beads. This can create pockets where ions bypass the resin, leading to a higher TDS reading.

• Small Canisters: Compact DI canisters are more prone to uneven flow, reducing resin efficiency.

Quick Fix: Reshaking the Resin

If your TDS is rising, you can try reshaking your DI resin cartridge:

1. Open the cartridge and remove the resin beads.

2. Shake and turn the resin to redistribute it evenly.

3. Reinsert the resin into the cartridge and resume operation.

This process can temporarily improve water quality and lower TDS, often giving you about an hour’s worth of optimal performance.

Storing DI Resin Properly

Many professionals carry extra DI resin cartridges in their trucks for quick swaps. However, resin can lose effectiveness if stored improperly.

Best Practices for DI Resin Storage

• Seal Air-Tight: DI resin absorbs ions from the air just as it does from water. Exposure to air can “kill” the resin, reducing its effectiveness.

• Keep in Bags or Containers: Store spare resin in air-tight bags or containers to prevent degradation.

• Avoid Excess Heat or Sunlight: Heat can accelerate the resin’s depletion, so store it in a cool, shaded area.

Following these storage practices ensures that your spare resin is ready to use and maintains peak ion-removal capacity.

Additional Factors Affecting RO Water Production

Even with proper pressure and resin maintenance, several other factors can influence the performance of your RO system:

1. Clogged Pre-Filters: Sediment or carbon filters can become clogged over time, reducing water flow to the RO membrane. Regularly inspect and replace pre-filters according to the manufacturer’s recommendations.

2. RO Membrane Age: Membranes lose efficiency over time. If your system is older than 2–3 years or shows consistently high TDS, consider replacing the membrane.

3. Tank Pressure: The pressure in the RO storage tank affects flow. Ensure the tank bladder is correctly pressurized (usually 5–7 psi for residential tanks).

4. Fittings and Tubing: Kinks or partially blocked tubing can restrict flow. Inspect connections and tubing for obstructions.

When to Consider Upgrades

For users who need higher water production or are using RO systems for professional applications such as window cleaning, detailing, or industrial purposes, additional upgrades may be necessary:

• High-Capacity RO Membranes: Larger membranes allow faster filtration and more water output.

• Advanced Booster Pumps: For high-rise applications or multi-story buildings, consider pumps with higher PSI ratings.

• Multi-Stage DI Systems: Using multiple DI stages or larger canisters can ensure consistent low TDS even under heavy usage.

Practical Example: RODI System for Window Cleaning

If you’re using an RODI system with a Gardiner water-fed pole system, water pressure is critical. For a 90-foot reach, you need roughly:

• 4.5 psi per 10 feet of pole height

• Total pressure needed: 40–45 psi plus system losses

Adding an impeller booster pump ensures that water reaches the top of the pole with sufficient flow for streak-free cleaning.

Similarly, maintaining fresh DI resin is crucial to avoid streaks or water spotting. Proper storage and occasional reshaking of resin beads ensure optimal TDS levels throughout the job.

Summary and Recommendations

If your RO system is underperforming, consider these steps:

1. Check incoming water pressure: Minimum 60 psi for optimal membrane performance.

2. Install a booster pump: Impeller pumps reliably add ~40 psi, improving flow and allowing for high-reach applications.

3. Maintain DI resin: Shake and redistribute beads if TDS rises; store extras air-tight.

4. Inspect pre-filters and membranes: Replace clogged filters and old membranes.

5. Check tank pressure and tubing: Ensure proper pressure and no obstructions.

By following these guidelines, you can maximize water output, maintain low TDS, and keep your RO system functioning efficiently for both residential and professional applications. Shop www.jracenstein.com for booster pumps and filter replacements.