Cache limit?

[Biscuit]

This is an area I don't know much about but it might rear it's head in future from other users.

I noticed that my server disk usage was suddenly a lot higher. The Bolt cache was at 350mb / over 6000 items. Is there a way to either limit this or have it's size more prominently displayed? I don't mind emptying it regularly but simply wasn't expecting it could be so much in less than a months use. If I've missed something obvious, point me in the right direction.