Citizen science (CS) projects engage citizens into carrying out scientific investigation together with professional scientists. It fosters open science and gives opportunity to the citizens to develop their knowledge and skills, therefore, it could be beneficial for students in school to be involved in CS projects as well. Estonian teachers have already adopted inquiry-based learning paradigm, but CS paradigm is new for them. Therefore, four schools in Estonia received Globisens Labdiscs with sensor technology enabling to collect scientific data about different aspects of environment with the aim to use these in CS related activities. Different subject teachers in these schools participated in four training events provided by the university learning specialists where they learned how to use Globisens Labdiscs and conducted hands-on inquiry-based and CS related activities. The aim of the current study was to improve teacher training so that teacher will adopt the new CS paradigm more effectively. During the trainings data was collected about teachers' technical skills of using the new technology, about how the teachers value CS related teaching outcomes, and teachers' previous experiences of using sensors and inquiry-based approach in school. Also, during the training events teachers created teaching scenario ideas for Globisens Labdiscs to investigate how the they will implement CS paradigm. The results show that 66.7% of the teachers had used inquiry-based approach in school before the training and after few training events this number grew up to 87%. Only 12.5% of the teachers had used sensors in their classes before, but this number grew up to 35% revealing that pure training did not motivate teachers sufficiently for the uptake of the new teaching approaches. Also, the results indicate that using the new technology was difficult for the teachers, but they developed their technical skills during the trainings. The teachers valued higher the teaching outcomes that came from the inquiry-based learning paradigm rather than the learning outcomes that came from CS paradigm. The study shows that CS approach has a great potential for using in school, especially with sensors based learning tools that enable solving problems with open science approach. However, the challenge is that at the beginning it is difficult for teachers and students to use the new technology. Adopting the CS paradigm may take time and participating more in real life CS project could help guiding teacher to implement the CS approach in their teaching.