Pro Sites Upload Quota to main site?

Hello Guys!

I'm facing a problem here... I'm using Pro sites to do a lot of things, one of this things is to limit upload quota... I activated it and went to network settings and set the space to 60 MB for the free sites, but the main site got 60 MB space... My main site is a BuddyPress site, so I can not limit this site's space, but I want to limit free sites to 60 MB only.

Is there a way to do that?