I use a 5 gallon bucket on a gravity feed for this reason. its so simple and if my float fails it wont overflow my sump because it can take a extra 5 gallons.  
I will donate any extras to you garry when your running although you used to be into a lot nicer corals than me. 
		
	
		
		
		
		
			
				__________________ 
				150 gallon reef mostly softies/lps. 50 gal sump with bubble magnus skimmer/ Led fuge light/refugium/ 1200 return and tunze powerheads. Dual pharoah main tank led.4 pump dosser. 
550 gallon stingray tank water drip system 
150 bowfront. 75 turtle tank, many others
			 
		
		
		
		
	
		
		
	
	
	 |