Disney's Percy Jackson and the Olympians promises to be a faithful adaptation of the books. With author Rick Riordan heavily involved in the production, every detail has been painstakingly sifted through to ensure connections to Riordan's Percy Jackson and the Lightning Thief. While the movies diverged heavily from the books just by changing the characters' ages, the show features a younger cast with more honest connections to the source material.
Source:https://www.cbr.com/disney-percy-jackson-series-changes/