you basically just "cloned" your mature filter. There was enough bacteria to handle to bioload of the single betta. Test once a day for a week and if stats still good, you can just do once a week testing and say, 30% waterchanges accordingly.
cheers!
				
			cheers!
 
	             
 
		 
	 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		