As i understand it, web space can fill up just like a hard drive, that's why posts are deleted after time. A forum will always 'fill up' the issue is more how much content you want to keep before you have to start deleting things, i.e. how far you want the thread in the forum to go back to.
There are people who will understnad this better amd i may be totally wrong, so I wait to be told i'm an idiot
