Amount of "Unknown" records is decreasing

Does anyone have suggestions for making IDing more interesting? I’ve been working on Unknowns, but it’s gotten so I can’t handle more than one page at a time. I’ve tried filtering by area, but it didn’t help that much. I need to do this, but it’s just so boring now, it’s hard to manage. Also, I would prefer to filter out the non-unknown observations in the pile (life is OK, but bacteria etc I cannot identify). What URL additions do I need for that?