I'm a believer in GFI outlets.My System is spread out over 6 seperate circuits, and each one is protected with GFI. Some of the circuits have multiple GFI in different locations. I don't use one GFI to run additional outlets for the simple reason that for the cost of the GFI, not shutting off additional equipment when it trips is of a greater value to me.
With over a dozen GFI installed I have to replace 1 about every 18 months.
All of my filtration equipment is located outside. So when the rains come (which they do sometimes in Sunny So Cal) there a couple of GFI that will trip.
I have however, had several device short and catch fire over the years. And when a piece of equipment starts shorting out, it does NOT trip the GFI, and it does not trip the circuit breaker.
So in addition to GFI, make sure you have a good fire extinguisher that you keep near the tank.
Dave B
It sound like you could benefit from an arc fault electrical breaker as well.