[banditpowdercoat]

A AFI would offer more protection, but I think one needs both?. A GFI will only trip if it senses current going to ground, not back on the neutral. One can have a short on a GFI, between the hot and the Neutral and it not trip. Conversly, a AFI only trips when it senses an arc. Be it to ground or neutral. Most cases a AFI would work. Not on halide lights, I'm not sure. But say a pump leaks some to the tank, a AFI won't pick that up, a GFI will. AFI's can also trip by just switching or unpluging components. Heaters can sometimes trip them as well.

Like everything in this hobby, nothing is foolproof