I downsized from a 90G to a RSM250 65g I used 60% old water from the 90G and 40%new water, all the rock that went into the RSM came out of the 90g sand was all rinsed with used salt water from the 90g. the bio in 2 bags were from my 50g sump which ran with my 90g and is hydrton balls, lr rubble and bio rings. 
Basically it was a big water change and worked great for me without any cycle. 
		
	
		
		
		
		
			
				__________________ 
				Hey! I never "LEFT" the hobby, just doing fresh water now. Which is still listed as part of Canreef if I'm not mistaken.    
			 
		
		
		
		
	
		
		
	
	
	 |