A computer-implemented method, according to one embodiment, includes: detecting that an error count resulting from reading a first page in a block of storage space in memory is above a first threshold, and reading a second page in the block of storage space. The second page is one which had a highest error count of the pages in the block of storage space following a last calibration of the block of storage space. Moreover, a determination is made as to whether an error count resulting from reading the second page is above the first threshold. In response to determining that the error count resulting from reading the second page is above the first threshold, the block of storage space is calibrated. Other systems, methods, and computer program products are described in additional embodiments.