Grounding Probes

Who has em and who doesnt? 

Who Swears by them and who thinks they are a waste????

Thinking about getting one but want to know if its worth it!

Justin

The purpose of the ground probe isn't to protect living things inside the aquarium, but to protect anyone who might be grounded and then sticks their hand in the water. The ground probe has less resistance, so the current flows through it instead of you.

I have never used a ground probe and have been keeping aquariums for 20 years. I have had a couple faulty powerheads/heaters, but have only ever felt a slight tingle from the stray current. There is potential for a deadly current, but I don't what the chances are of that happening. This may be because I have always used a GFCI outlet, which disables the outlet if it detects current flowing outside the circuit.

In short:

If you care more for your/your families safety then the aquarium inhabitants, use a ground probe/gfci.

If you care more for the safety of your aquarium inhabitants than yourself, don't use a ground probe.

I believe we would all agree that the ocean is grounded, right? The idea of having our little piece of the ocean connected to the ground makes sense, right? Yes, but here's where the difficulty arises.

If the insulation on an electrical component breaks, electrical energy comes in contact with the tank water. Sitting in this glass/plastic box the electricity has nowhere to go (Unless the insulation breaks on both wires. This makes a short circuit through the water immediately surrounding the break).

Where a grounding probe is present, the stray electricity runs from the break to the grounding probe. As it travels through the water, it shocks anything in it's path. Salt water does not carry electricity as well as copper wire so the electricity has to spread out to reach the grounding probe. This essentially electrifies the entire tank.

Where a grounding probe is not present, the electricity is waiting to go somewhere and will move to any place it can. When we poke our hand into the water, a tiny amount of electricity will move to our hand, but as long as we are not touching something else, even another person, standing or kneeling on wet surfaces, the electricity will stop and not travel through our body. (In H.S. Vocational Electronics our teacher had us hold hands in a circle around the classroom to complete an electrical circuit, while he gradually increased the Voltage but kept the Amperage at very close to zero. As I recall most of us let go as the Voltage neared around 40 Volts.)

I believe that the concern with electricity in our aquarium should not be whether a grounding probe is used or not used, but rather, whether or not all our electrical equipment is properly insulated. There is an easy way to check this with a voltage meter. Set the meter for 100+ Volts AC and with one probe touching the round ground socket of a wall outlet or power strip or held tight against the grounding probe while it is removed from the water, place the other probe into the tank water. If the voltage reads higher than about 40 Volts, especially if it reads over 100 Volts, there is an insulation problem. (Voltage below 40 is normal ground voltage.) To find the faulty item, unplug things one by one until a sharp drop in voltage is seen. That item is the culprit.

I should also add that unless a grounding probe and electrical equipment are plugged into a GFCI protected circuit, the purpose of the grounding probe to prevent electrical issues like shock and fire is thwarted.

Also, when the GFCI trips/breaks the electricity and all power to the tank is lost for many hours, there may be more serious matters to deal with. For this reason I suggest that one circulation pump or the return pump be connected to an ordinary outlet that won't go off accidentally. Some hobbyists reported that the GFCI was tripping accidentally for no good reason leaving their tank to teeter on the edge of a crash because of no water movement.

Electrical safety is very important. I solidly attach power strips upside down inside the stand, away from where salt water could accidentally drip into the socket. (Right here in the WMAS, fires have been caused by salt water dripping on electrical connections.) This also makes for easy, one handed unplugging. 

Aloha,

Mark