i have eggcrate and i covered it with about 1.5in sand all around 
the high flow areas started to show the eggcrate but now that its about 7 months in, i started moving around the sand just enough to cover the eggcrate and its starting to stick better. 
		
	
		
		
		
		
			
		
		
		
		
	
		
		
	
	
	 |