This paper presents a novel and practical screen-space liquid rendering for particle-based fluids for real-time applications. Our rendering pipeline performs particle filtering only in a narrow-band around the boundary particles to provide a smooth liquid surface with volumetric rendering effects. We also introduce a novel boundary detection method allowing the user to select particle layers from the liquid interface. The proposed approach is simple, fast, memory-efficient, easy to code and it can be adapted straightforwardly in the standard screen-space rendering methods, even in GPU architectures. We show through a set of experiments how the prior screen-space techniques can be benefited and improved by our approach.