That would be an affirmative, however, all the GFCI is searching for is a direct short to ground, which is also your neutral wire, which is also grounded.
If you have a two prong plug, which would tell me that you should have a new grounded outlet installed especially around a fish tank.
But if you want that info why didn't you just google it?
Overview
Protects from electrical shocks
Plug into any 3-prong dual outlet
Converts electric outlet into safety outlets
Essential Info
Protect your electronics from destructive power surges! By plugging your expensive components into the Shock Buster 5-Outlet GFCI, you'll be protecting them from the electrical shocks that could damage them irreparably. Best of all, you'll actually get more outlet space: It may plug into two outlets, but the Shock Buster 5-Outlet GFCI can handle five separate components at once.
What's Included
Outlet
Instructions
More Info
No installation is necessary; just plug the Shock Buster ground fault circuit interrupter into any 3-prong dual outlet. The electronic sensing device built into the Shock Buster instantly detects leakage currents as low as 4mA and in a fraction of a second turns the power off to prevent injury and to avoid electrocution.
Additional features include test and reset buttons.
If you need some assistance I can help you.