[Ashley Weed]

There are two red "vision" tetras on the field, and two blue "vision" tetras on the field at the start and during game play. I would assume that leaves 36 tetras to be placed on the field or manipulated during game play. However, take into account, that if a tetra is not "de-hung" from one of the larger tetras, it will be removed from game play, which could leave you with up to four less tetras.