Electrical question

[Black Phantom]

By code you have to have a GFCI in your bathroom in case you drop your hair dryer into the sink full of water. Or reach into the water when holding your hair dryer.
Obviously there is no ground probe in your sink. Isn't it the same thing with your aquarium?
I'm really in the dark here and just don't want to find myself floating over my lifeless body on my way to who knows where

Hopefully up

[spreerider]

your sink should be grounded if its metal and it its not it wont matter as it wont conduct anyways.

A GFCI works by measuring the current entering (hot) and leaving (the identified conductor commenly called neutral) you can have a ground fault and not have a gfci trip under the right circumstances but a solid connected ground is not necessary for a GFCI to trip as the current in a fault without solid ground could still make it to ground via a person or object.
i use a GFCI but no ground probe.
BTW most aquarium products are not grounded they are double insulated you can tell because none of them have a 3rd prong on the cord, the only thing that usually is grounded is the light as some require a proper ground to startup lights, and often have exposed metal on the fixture that needs to be grounded as per CEC and CUL.