1. Introduction: Small System, Big Design Challenges While the scale is smaller than an industrial plant, designing a high-end commercial or residential Reverse Osmosis (RO) system requires the same level of engineering precision . In fact, the challenges can sometimes be trickier: space is limited, budgets are tighter, and aesthetic integration is critical. A major pitfall is relying on off-the-shelf, one-size-fits-all systems. Without a custom design based on your specific water chemistry and daily usage, even a small system is susceptible to premature failure. My remote consulting service applies industrial-grade design principles—focusing on accurate sizing and custom pre-treatment—to guarantee peak performance for your low-capacity application. 2. The Golden Rule: Accurate Sizing is Key The most critical factor in designing any low-capacity system is determining the required Daily Production Capacity (GPD or m 3 /day) . * Residential: Must acc...