The strength of top-down (consumer) control in stream ecosystems is known to vary across temporal and spatial scales. Although little is known about whether measurements at the small scale can be ‘scaled-up’ to describe what is occurring at the catchment level or larger spatial scale. Here we conducted a 40 day consumer manipulation experiment (i.e. fish and shrimp removal) to test top down consumer effects and in-stream processes within three streams in the wet/dry tropics of northern Australia. Changes in benthic algal biomass as well as macroinvertebrate abundance and community were measured at the patch scale within small 1m² exclusion cages and at the reach scale within whole-reach exclusions (~20m). At the reach scale strong top down consumer effects were observed, with evidence of a trophic cascade. Here the removal of consumers resulted in a significant increase in macroinvertebrate abundance and a significant decrease in benthic algae biomass. However at the patch scale, there was no evidence of top-down effects, with no significant difference in macroinvertebrate abundance or benthic algae biomass between treatment groups. Our findings highlight the difficulty in ‘scaling-up’ top-down control results. This is particularly important for river health monitoring which is typically challenged by the need to “scale-up” from site level measurements to the whole ecosystem which is frequently the target of management actions; as many of the human induced pressures on our riverine environments occur at large scales.