What are these Hitchhikers? :)

[Alberta_madcow]

Ya 50% water changes every 2 days... It's been ok so far. Ph is perfect, ammonia 0 ppm, nitrite 0 ppm, nitrate still at about 10 ppm it should go down after tomorrows water change. Almost ready for a few critters! Everything that came on the live rock is still alive too!!