Quote Originally Posted by LOC NAR on probation
Good advice. You may be surprised, the root ball will tear up 2 inch if they get too big.
I ran 3 inch because you don't need all that space unless you want tree's. I had a few that got over 4 feet tall. No problems.
That's true, but considering how cheap a net pot is having this happen isn't a catastrophe. The biggest problem is that you might have some medium fall into your reservoir.

If you find out your cups are too small for your first grow (because they rupture) it's not a problem to just get bigger cups and cut bigger holes to fit them for the next grow.