This shortens the life.
													
																	Can i use a 400w bulb in a 250w ballast. 
									
	
		
	
																	Same applies with the ordinary lamps in your house. 
																	The 250w lamp will burn hotter and a little brighter than normal but will use almost as much power as a 400w lamp. 
																	The ballast is trying to push that 400w into the 250w lamp. 
																	On the other hand in breakdown service if a lamp roasts and during a few days before the new purchase one can without risk use 1 ballast 400 per 1 lamp 600 the ballast does not put has the lamp badly to in no case. 
															
													
									
	
		
	
																	I would think that the ballast is rated for a max 400w. 
																	Lamp 400 ballast 400 etc. 
																	If someone has experimented with a light meter and temps proving this is safe i would like to hear the results. 
																	Two grows seems a little soon to replace the bulb. 
															
													
									
	
		
	
																	The ballast is able to provide 400w. 
																	Lamp 250 ballast 250. 
																	Don t put a stronger light on it though. 
																	The ballast is trying to push that 400w into the 250w lamp. 
															
													
									
	
		
	
																	I don t think it would work the light is only capable of using 250w. 
																	If you look at a 400 and 250 ballast side by side the 400 is bigger. 
																	From all that i have read about mh s you can t run 250 watt bulbs on a 400 watt ballast. 
																	This shortens the. 
															
													
									
	
		
	
																	I was considering changing the bulb as it has done 2 grows so should i buy a 250w or 400w bulb. 
																	Attaching a weaker light shouldn t hurt anything. 
																	Use the proper setup.