In this project we have developed an open-source implementation of an OPT platform, built around a customized sample stage, 3D-printed parts and open source algorithms optimized for the system. We have developed a versatile automated workflow including a two-step image processing approach for correcting the center of rotation and generating accurate 3D reconstructions. The system is optimized for imaging of young zebrafish, and rapid loading and unloading of samples enables analysis of a large number of fish. The system has been used in several projects at the zebrafish facility, Genome Engineering Zebrafish, SciLifeLab.