The tank is glass. 
 
I dont know if it makes a difference but its only a 50 gallon with a small foot print 36x16 inches.  
 
If I do go ahead and remove most of the sand can I replace it all without creating a problem. The sand bed is 3 to 4 inches deep and in some locations deeper in the bed there are black areas. Its my understanding that these areas if disturbed can release gasses into the water. Will i have to replace all the sand? 
 
Thanks for all your replys so far. Keep them coming 
 
Josh 
		
	
		
		
		
		
		
	
		
		
	
	
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