This dataset is from the second of four experiments which test the toxicity of several metals with aquatic insect communities that were colonized in the field and then transferred and tested in experimental streams. Here we report original data from testing the toxicity of cadmium (Cd), zinc (Zn), and copper (Cu) singly and in mixtures, to natural aquatic insect communities. Thus, the exposures reproduced those in experiment 1, with the addition of a third metal, Cu Trays of cleaned gravel were placed in a stream (the Cache La Poudre River, Colorado) and allowed to colonize for about 40 days before being translocated to Aquatic Experimental Stream Laboratory (AXL) which was located at the USGS Fort Collins Science Center. There the insects were exposed for 30 days to metal mixtures in ratios and concentrations similar to those occurring in ambient conditions. Emerging adult insects were captured and collected daily throughout the experiment, while larvae and metal residues in periphyton, sediment, and Brachycentrus caddisflies (a common, large-bodied, robust taxa that could survive high metals accumulations) were collected on the final day of the experiment.