That all depends on water and flow rate. The higher the water flow, the more air you need.
The 3" line to the 7" hamster balls are only good for 2000 gph.
The screened Koi Toilet 2 is 4", will handle much more flow, and it has the nice wife flange for clamping onto the side of the thin tank.
There are lots of choices for an air diffuser, such as soaker hose, an air stone manifold like pictured, or the good old 9" high capacity air diffuser. (my favorite, just crank up the air amount).