User blog comment:Tekkphreke/The Balance/@comment-10579249-20130721203832

If they killed 2,000 in the Soul society, then they'd have to kill 1,000 in the human world to balance it back out. However, if they sent the Visoreds to Hueco Mundo to kill 2,000 hollows, it would solve the issue.

However, wasn't the original problem that the Quincies were killing off hollows in Hueco Mundo and not the Human World? When Ichigo and Co arrived there, they mentioned the lack of hollows and saw large piles of their bodies so that could've been what was throwing off the balance in which case all they have to do is go back to Hueco Mundo and kill 1000 more.