As technology continues to reshape education, the integration of peer feedback (PF) is increasingly recognized as a key element in promoting student collaboration and learning. This design study tracks the development and implementation of the Thinq Tank tool, which is aimed at facilitating dialogic PF within computer-supported collaborative-inquiry learning (CSCiL) environments. The research was conducted through three design iterations, comparing two key experimental conditions: one contrasting non-dialogic PF with dialogic PF, and another comparing dialogic PF with scripted dialogic PF featuring dynamic sentence-starters and defined roles. Utilizing a quasi-experimental design, we assessed the overall impact on scientific (collaborative) learning outcomes, students’ perceptions of PF, and the composition and elements of PF dialogues. The findings suggest that the integration of dialogic PF within a CSCiL lesson series helps to boost scientific collaborative learning outcomes and increases student receptivity to PF. The study demonstrates that integrating structured support mechanisms within PF tools promotes PF dialogues in which students critically evaluate each other’s work and collaboratively think about ways to improve quality. These insights illustrate that structured, technology-supported PF can significantly advance inquiry outcomes and foster deeper collaborative learning in secondary STEM education.