A method of optimizing a read threshold voltage shift value for non-volatile memory units organized as memory pages may be provided. An ECC check is performed for active page reads. The method comprises, as part of the read operation, determining a status of the memory page, and reading a memory page with a current threshold voltage shift (TVS) value. Additionally, the method comprises, upon determining that a read memory page command passed an ECC check, returning corrected data read, and upon determining that the read memory page did not pass the ECC check, adjusting the current TVS value based on the status of the memory page to be read. Furthermore, the method comprises, while the read memory pages continues to not pass the ECC check, repeating the adjusting the current TVS value and the determining that the read memory page passes ECC check until a stop condition is met.