Originally Posted by
jamie814
The grounding probes are not sold to protect the aquarist working in the tank they are sold to protect the inhabitants on the tank from the potentially constant stray voltage that has been linked to head and lateral line erosion.
You're right that that is what they are SOLD FOR, but that's not really what they DO. A ground probe is sold as a magic device, a buzz word, a cure all for everything from neurological disorders to HLLE.
Although we bashed him, Saltfan made a good point. If there is no place for the power to go, you have no stray voltage.
Most electrical failures in a tank are the result of water coming in contact with an electrically live part of defective equipment. Unless there is someplace in that tank to complete the circuit, there will be no "stray voltage." It's just a buzz term, industry hype that helps sell aquarium gadgets. If a live wire is exposed to the water but there is no ground or other path to complete a circuit, no current will flow. Contarary to popular belief, there are no electronic gremlins swimming around waiting to attack the head of a Sailfin Tang or Emperor Angel. The mere contact of a hot wire with water will not cause stray voltage. In order for electricity to do ANYTHING, it must be allowed to flow in a circuit. That's why birds can sit on electrical wires, they are only touching one wire and are hence not part of the circuit, and we don't really hear about "Head and Lateral Feather Erosion (HLFE)."
There are those of you who are ready to jump on me and say "Well I stuck my meter into the water and read voltage, and I don't have a grounding probe ROFL LOL WTF!!!!1111" If that's true, then your water is grounded through something else, or you have two separate pieces of equipment that have failed and completed a circuit from one to the other.
What hurts the fish is the presence of a current flow within the water. That requires something grounded, such as a titanium heater tube, chiller heat exchanger, grounded submersible pump, or grounding proble. That's right, a grounding probe actually HURTS, unless it's paired with a GFI to cut that power off. Saltfan argues that without a grounding probe, since no circuit can be completed in the tank, there is no stray voltage. He's absolutely right, but it does cause a safety issue to the aquarist.
Long story short... don't fall into this stray voltage crap. A grounding probe needs to be used with a GFI, it does not "drain away" or "neutralize" voltage. All it does is assist a GFI in doing it's job.