Slater played sparingly during two years at Tulane, averaging 2.7 points per game as a sophomore. He opted to transfer to Long Beach State and sat out the 2018-19 season as a redshirt.[2] Slater averaged 10.2 points and 2.4 rebounds per game as a junior. He initially decided to opt-out of the 2020-21 season due to COVID-19 concerns but opted-in after the fall semester.[3] Slater was named the 2022 Big West Player of the Year after helping lead Long Beach State to a regular season Big West title.[4] He averaged 14.4 points and 2.8 rebounds per game.[5]