They only get a max of 2.5-3" -- so not much bigger than they are now.
They're a loose pair at this point - no signs of spawning, but that's because my water is too hard. Gotta get it down if anything is to happen (and I plan on it).
Also, apisto males like to have "harems" of females to choose from -- but I doubt I'll find another female or two of this species around here. We'll see if this pair hits it off once I get the water right, though.