If you don't want to farm Alex, other good sources of light are Expert and 60 roulettes, the 24-man raids, and Frontlines Seal Rock/Fields of Glory as well as any HW bird farms.
A lot of my light came from pvp. So in addition to all my relic weapons, now I also have all the Garo mounts, a Storm cavalry horse, and a white ADS. (And pretty good pvp rank on my server!)
But yeah, Void Ark is quick and easy. Also, you can just spam level 60 dungeons. I got tired of A1S so I did most of my light through other methods and still finished up that step in about a week and a half for most.
