Thanks to everyone who take their to read this thread.
please guide me.
Welcome to the commmunity!
You would need to put this in /conf/config.php and change the number to what you need:
$Configuration['Vanilla']['Discussions']['PerPage'] = '30';
Add Pages to Vanilla with the Basic Pages app
Thanks for reply
I checked this file and there no such line :-s
Oh I'm nuts! I didn't read it carefully. I thought I have to find and change the amount. thanks