Hi Deep six! Welcome to the forum. 
 
It's probably worth noting the difference between surge protectors and GFCI's. 
 
A surge protector protects delicate electronics from surges originating from the grid (lightning strikes, transformer accidents).  
A GFCI prevents an electrical component from drawing too much power from the grid (malfunctioning heaters, knocked in lights). 
A surge protector won't prevent electrification of the water but a GFCI will. I don't know if it would have helped in this case but a GFCI's reaction time is in milliseconds. A grounding probe is useful in removing random stray voltage but it would not help in a large way in this situation. The grounding probe would try to draw off the unrestricted voltage from the heater but it could not turn the heater off. Only a GFCI or a blown fuse/breaker would do that. 
 
As you can tell I am a big fan of GFCI's and I try to install them in every system I set up. I have already had a client that had her arm elbow deep in the tank when she knocked the actinics in. She received a small shock but the GFCI worked and tripped off the power supply. 
		
	
		
		
		
		
		
	
		
			
			
			
			
				 
			
			
			
			
			
			
				
			
			
		 
		
	
	
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