This is quite a good article discussing connection pooling:
Perhaps if you give some more details as to what your problem is, and why you think that increasing the size of the pool will help, someone here might be able to guide you better.
answered Oct 21 '09 at 11:37 AM
Melvyn Harbour 1 ♦♦
ADO.NET Connection pooling page: http://msdn.microsoft.com/en-us/library/8xx3tyca.aspx
Also check your server max connections setting on SQL Server, this will reset it...
Hope it helps.
answered Oct 21 '09 at 03:06 PM