Multiple representations are ubiquitous in chemistry education. To benefit from multiple representations, students have to make connections between them. However, connection making is a difficult task for students. Prior research shows that supporting connection making enhances students' learning in math and science domains. Most prior research has focused on supporting one type of connection-making process: conceptually making sense of connections among representations. Yet, recent research suggests that a second type of connection-making process plays a role in students' learning: perceptual fluency in translating among representations. I hypothesized that combining support for both conceptual sense making of connections and for perceptual fluency in connection making leads to higher learning gains in general chemistry among undergraduate students. I tested this hypothesis in two experiments with altogether N = 158 undergraduate students using an intelligent tutoring system for chemistry atomic structure and bonding. Results suggest that the combination of conceptual sense-making support and perceptual fluency-building support for connection making is effective for students with low prior knowledge, whereas students with high prior knowledge benefit most from receiving perceptual fluency-building support alone. This finding suggests that students' learning in chemistry can be enhanced if instruction provides support for connection making among multiple representations in a way that tailors to their specific learning needs.