what you just experienced was sheer bad luck...just make sure you don't get firefish, even though i read many times people still can keep them with open top.. 
 
not many fish jump at all.... and if they did jump it might be a reason to it.... 
 
I wouldn't bother covering up your tank due to one small dumb damsel... risking your tank over boiling! 
		
	
		
		
		
		
		
	
		
		
	
	
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