This study aimed at (1) evaluating the effectiveness of inquiry learning model; (2) consistency of inquiry learning model impact; and (3) identifying differences of consistency of inquiry learning model impact in improving the prospective teachers' metacognition knowledge and metacognition awareness in learning about fluid. This study was a weak-experimental research since there was no control class. There were three experimental classes in order to find consistency within the results of the study, which was also designed as one-group pretest-posttest protocol. Samples in this study were 90 students, which were distributed into three groups by using saturated sampling technique. Metacognition knowledge tests consisted of 20 items asking about description, while Metacognition Awareness Inventory (MAI) was used to collect data about metacognition awareness. Results showed that metacognition knowledge and metacognition awareness of samples from three groups were significantly varied after being engaged in learning (p < 0.05). The impact of applying inquiry learning model was not significantly varied (p> 0.05), but only on samples' metacognition awareness among Group B and Group C. The inquiry learning model was proven effective in increasing samples' metacognition knowledge and metacognition awareness in learning about fluid. However, the impact was inconsistent in all three experimental groups.