Log in or Sign up

Article on Grounding Probes... Agree?

Discussion in 'General Reef Topics' started by Chad, Jan 3, 2010.

Join 3reef now to remove this notice and enjoy 3reef content with less ads. 3reef membership is free.

Page 1 of 2

Chad Astrea Snail

Joined:

Dec 7, 2009

Messages:

51

Location:

Manalapan, NJ
Do you folks agree or disagree with this article, I found it interesting. I'm still undecided.

Conventional wisdom found in magazine articles and in the bowers of world wide web chat rooms indicated that “voltage” in aquaria is one of the factors that can cause Hole in the Head and Lateral Line Erosion. We read quotes like, “Stray voltage is something that exists in every tank. Stray voltage can be eliminated with a simple ground probe available at most pet shops in the twenty dollar range. Elimination of stray voltage is a simple step in reducing the stress on your fish. Every marine tank should be grounded for your protection and that of your fish.”
Is it true? Well not exactly, and as I will discuss below, the addition of a ground probe may even make matters worse!
Clearly electrical items submerged within your aquarium (power heads, heaters, etc.) can provide a direct interface between the prime power source (120 volts alternating (60 Hz) current (VAC) in the United States and 220 VAC, 50 Hz in most of the rest of the world) and the water, but some claim that the stray voltages can be indirectly induced by the lighting systems. This is possible because the skin depth of salt water (a conductor) at 60 Hz is not zero. “Skin depth” is the distance that electromagnetic energy can penetrate a conductor. Salt water is a conductor, but not a perfect conductor, so there is penetration by 60 Hz emissions. These induced voltages are small in magnitude. On the other hand, shorted pumps can develop large currents through the water, but typically between the “short” and some “ground” like your ground probe. This means that the inclusion of a ground probe could make things worse. If a pump were shorting within itself, the currents flowing through the water would remain local to the pump and should not be a problem. You would have to have two shorting pumps, or a pump and a ground probe, or some other current path to get electrical current to flow through your tank.
Direct shorts would have other ramifications. Copper or iron could be introduced into the aquarium water as plating occurred. Other compounds would plate out as well since salt water contains many ions in suspension. Electrolysis would occur, heating the water while it liberated oxygen and hydrogen. There is of course a shock hazard.
Most people do not understand the problem however. Lots of web space has been devoted to the measurement of voltage in aquariums... most of which is of no value. Voltage is not the problem, current is. Voltages can exist without there being any current. For example, birds sitting on a power line may be in direct contact with 10,000 volts, but they are not electrocuted. Why? Because no current is flowing through their bodies. Voltage is the “potential” or force that drives electrons through a conductor. The actual flow of electrons is the “current”. It is current that kills. Were one of the birds sitting on the power line to simultaneously touch one of the other wires on the transmission pole, a current path would be created (through the bird) and it would be electrocuted (and probably incinerated as well). So what are you doing when you add a grounding probe to your aquarium? You are providing a current path that might not already exist. Any fish between the source and the grounding probe will experience a current flowing through their bodies... not good!
Taking a volt meter and measuring a voltage in your aquarium relative to some arbitrary ground point does not indicate that there is a current flowing through the salt water (conductive medium) in your aquarium! It just means that the aquarium water is at a different potential than the ground reference point that you chose.
Measuring a voltage between submerged points in your aquarium may be misleading if not done correctly. The use of metallic probes can create a “battery effect” if dissimilar metals are involved (think your volt meter probes are the same metal? What if they are chrome plated (most are) and what if you’ve worn the chrome off one to expose brass or copper beneath?).
Also, some currents in salt water are perfectly natural as described below.
You can measure electrical currents everywhere-- the fact that salt water ions flow, actually generates an electrical current. Its unavoidable. The open ocean has lots of electrical currents flowing. Some of these are caused by currents flowing through the Earth while others are actually perturbations to local fields caused by the motion of objects (fish, turtles, etc.) in the water. When I was tracking the Florida Manatee (Trichechus manatus) in the Banana and Indian Rivers around the Kennedy Space center, we actually considered sensing the extremely low frequency (ELF) emissions generated by the manatee’s tails as they accelerated the brackish or salt water ions in the presence of the Earth magnetic field during vigorous swimming (alas, manatees are not very energetic most of the time and other means were chosen (Sirenian Tracking Project)). For example, the ampullae of Lorenzini in a shark’s nose detect minute current flow disturbances in the water as an aid in locating prey.
I don't use any power heads and all of my pumps are totally external and physically isolated (motor and pump head are separate). With the exception of an emergency heater in the sump, no electrical appliances come in contact with the water.
There are all sorts of anecdotes about how much better the fish in a given tank will act and look after adding one of these “grounding probes”. My belief is that if there are any stray currents in the tank coming from an electrical appliance, the solution is not to try to draw the current away with a grounding probe (symptom), rather, the appliance must be damaged and should be replaced (cure).
Fish don’t like electrical current to flow through their bodies. When higher electrical current levels flow through the water, fish will orient their bodies to minimize the potential (voltage) across their bodies, thereby minimizing the electrical current flowing through their bodies. At very low levels, the fish may only act strangely or seek areas of the aquarium where electrical current is not flowing. It is doubtful that continuous current flow through a fish’s body is beneficial, and may in fact be the source of anecdotal reports of Hole in the Head disease and Lateral Line Erosion. If your tank is at a different potential from the “ground” in your house, no electrical current may exist in your tank based on this static voltage. However as soon as you ground your tank by inserting a “grounding probe”, you will be guaranteed to have electrical current flowing even if the voltage drops.
For a technical discussion of stray voltage in aquaria and the use of Ground Fault Interrupters, click here.
In conclusion, the addition of a “grounding probe” will guarantee an electrical current flow in your aquarium and may induce erratic behavior or disease in your fish. If you have defective aquarium appliances that are creating a current path in your aquarium by using the salt water as a conductive medium, then the solution is to repair the appliances or replace them... not divert a portion of the current into a “grounding probe”.
Click to expand...

Aquarium Grounding Probes

Chad, Jan 3, 2010

Chad, Jan 3, 2010

#1

thepanfish Flying Squid

Joined:

Jan 1, 2010

Messages:

3,014

Location:

Michigan
I read that online and am in the same position as you... undecided. Although it is a good argument, I hear they are recomended by many professionals and LFS.
What to do, up to you, I'm sure someone here will know more...

thepanfish, Jan 3, 2010

thepanfish, Jan 3, 2010

#2
Robman Great White Shark

Joined:

Jan 22, 2009

Messages:

2,688

Location:

Katy, Tx.
Everytime this comes up, it creates a war....http://www.3reef.com/forums/general-reef-topics/do-you-use-ground-probe-why-63790.html

Robman, Jan 3, 2010

Robman, Jan 3, 2010

#3
elweshomayor Giant Squid

Joined:

Jul 6, 2009

Messages:

3,964

Location:

Norcross, Atlanta Ga.
Pretty interesting. Idk if I agree but it's pretty convensing. I remember all that stuff from physics class and it all makes sence.

elweshomayor, Jan 3, 2010

elweshomayor, Jan 3, 2010

#4
unclejed Whip-Lash Squid

Joined:

Sep 23, 2008

Messages:

2,964

Location:

Clinton Township, Michigan
The assertion that, if something is leaking electricity it will stay in the vicinity of the object is absurd. The electricity goes out somewhere (in the water) and strays as water is a conductor. The straying electricity is the problem. A grounding probe routs the stray electricity out of the tank. Perhaps a current is formed, however, it is concentrated and directed now instead of stray. I believe fish know to stay out of the electrical current.

unclejed, Jan 3, 2010

unclejed, Jan 3, 2010

#5

TritonsGarden 3reef Sponsor

Joined:

Jun 14, 2008

Messages:

541

Location:

Lawrenceburg, TN
Robman said: ↑

Everytime this comes up, it creates a war....http://www.3reef.com/forums/general-reef-topics/do-you-use-ground-probe-why-63790.html
Click to expand...

That is why I will not argue about it. I will say that I have been an electronic technician for 30+ years and I will not use a grounding probe.

Jack

TritonsGarden, Jan 3, 2010

TritonsGarden, Jan 3, 2010

#6

pgreef Fire Goby

Joined:

Dec 6, 2008

Messages:

1,344

Location:

Algonquin, IL
Yes, I absolutely agree with this article. I have a Master's degree in electrical engineering and the article is correct. I use a grounding probe only for my own protection, not the inhabitants' protection. Placing a grounding probe in the tank does provide a current path exit for the tank and can induce more current in the tank. It also makes it the same voltage potential as hour house ground.

A ground probe, combined with a GFI outlet, will provide the aquariast and his/her family with the best protection possible. The GFI should respond as soon as something fails if a ground probe is used. Without a ground probe your GFI may not trip until somebody sticks their hand in the tank.

pgreef, Jan 3, 2010

pgreef, Jan 3, 2010

#7

1 person likes this.
PharmrJohn The Dude

Joined:

Jun 29, 2008

Messages:

4,622

Location:

Shelton, Washington
pgreef said: ↑

Yes, I absolutely agree with this article. I have a Master's degree in electrical engineering and the article is correct. I use a grounding probe only for my own protection, not the inhabitants' protection. Placing a grounding probe in the tank does provide a current path exit for the tank and can induce more current in the tank. It also makes it the same voltage potential as hour house ground.

A ground probe, combined with a GFI outlet, will provide the aquariast and his/her family with the best protection possible. The GFI should respond as soon as something fails if a ground probe is used. Without a ground probe your GFI may not trip until somebody sticks their hand in the tank.
Click to expand...

There you go. I agree. I run both for this reason.

PharmrJohn, Jan 3, 2010

PharmrJohn, Jan 3, 2010

#8
jonjonwells Great Blue Whale

Joined:

Dec 9, 2008

Messages:

2,835

Location:

SE Kansas
Fish are cheap. Protect yourself.

I had a pump that the insulation on the cord cracked. I juked myself real good. Run one all the time now.

jonjonwells, Jan 3, 2010

jonjonwells, Jan 3, 2010

#9
ZachB Giant Squid

Joined:

Oct 12, 2008

Messages:

3,111

Location:

Earth
I do not run a grounding probe.

ZachB, Jan 3, 2010

ZachB, Jan 3, 2010

#10

(You must log in or sign up to reply here.)

Page 1 of 2

Search