I have 2 albino plecs as well. They love romaine lettuce and seedless cucumber slices. When I first bought them, they were soo tiny that I could barely find them in my tank as well. One time I picked every decoration out of my tank looking for the one but was unable to find him. I looked in the hob
filter box and there he was. He likes it in there sometimes.. maybe the strong current? Who knows, but from then on out any time I couldn't find him, i'd know to look in the filter box.
Btw, Congrads on the fish, you'll love em!