wattsupdoc
New member
That is the question. I'm sure this forum has had it's discussions involving this. They all have. As well you'll find many on both sides. You'll even find those that sway to the side of not GFI protecting their tanks. Here's my take on the matter.
Electricity and water do not mix. While pure H2O is not conductive. Most all water is. This is because of the things in the water column. Metals, DOC's, chemicals, nutrients, etc. are all what make the water conductive. Because SW aquariums have many different things dissolved in the water, with a rather high specific gravity, it is conductive. We have tons of electrical components submerged and surrounding our aquariums. All of these things have the potential to become damaged in some fashion and cause water to enter the compartments that are usually insulated from the water. Cords can also become damaged and cause a hazard. As well as water or salt even contacting these areas. Put your hand in the tank with this hazard and become grounded sufficiently and it "could" mean the end for you.
The probe.
The idea behind the probe is that it gives the current somewhere to go, should this situation arise. You wont know that it has under many situations, the electricity is basically being "drained" from the column. In circumstances where the damage to the electrical part is sufficient enough, you would likely see a breaker tripping, but it most scenarios this wont happen. There are many factors that can be involved in what will actually occur when a piece of equipment goes faulty and we can decide what will actually happen when yours does. Those who are against the probe are so mostly because it creates a path, effectively grounding the water column, and therefore touching the water then touching a piece of faulty equipment(even something in the area not associated with the tank) can cause you to be shocked. As well as those who don't believe the probe does what it is designed to do. Like most things, there are several ways to connect the probe, and many of them do not guarantee that it is correctly connected. I have seen many threads directing an individual to "connect it to the ground on the receptacle". While this in many cases should guarantee an effective ground, it does not always. The average aquarist has no way of knowing if it is, but believes that it is. Now they are under a sense of false security which makes for a hazard in itself.
How do you know?
Unfortunately, there is no sure fire way to tell by looking. The NEC requires all homes to be grounded to the Earth with an electrode. There must not be any more than 25 ohms to the ground in this connection. Basically, what this does is insure that any shorted circuit has a direct path to go to should it need to. Having a driven rod connected to the panel is one method (and the most common) of doing this. HOWEVER, it does not always guarantee this. Using a ground rod tester is one way to know how well of a ground you have. However, these are not cheap and not something you can just go to Ace and purchase. Calling a qualified electrician and having them come to your home and doing this test is an option. Be sure to ask if their shop has one and tell them what it is your wanting to do. There is something else that a homeowner could do that would most likely always guarantee the connection is good. That would be to run a second additional ground rod, 6 foot from the existing one. Then connect the two rods together with a piece of #6 copper wire. This is considered a ground rod set. It is a very effective means of accomplishing an assured low impedance ground to a home. Now if you can connect that little rod in the DT directly to these rods. You now are sure of your connection. Otherwise, you rely on your homes wiring(which should be good enough on a modern home) to make this connection to the rods. There are scenarios where this connection might not be adequate or even become degraded. Mostly these are relative to inferior wiring practices during the time the home was built and/or age of the home.
Overall, IMO, I can say that a properly connected ground probe should be a part of every aquarium. But only to be used in conjunction with a GFCI of some sorts, preferably 2 of them. I prefer to use the plug in style GFCI's. You can get these at any home improvements store. They simply plug into a receptacle, then plug you plug strips into these. If one goes bad, simply unplug it and replace it.
GFCI'S
This stands for ground fault circuit interrupter. This is a safety device which disconnects power to an appliance or other electrical equipment whenever it detects there is a problem with a short...essentially. How exactly it does this is not as important here as is why it does it. It does this to protect you from electrocution in the event that something comes in contact with water you are or could be also in contact with. These are very good at doing their job and do it quite quickly. IMO, they are a must for an aquarium. However, using only one can be a hazard for your tank mates. If it should trip while you are not around. All equipment connected to it would be off. Not a good thing with life support. I personally recommend using at least 2 of these per aquarium. Splitting all life support systems up so as to continue to maintain as much as possible should a trip occur.
Stray Voltage, shmay voltage.
This, additionally is something of great debate. You see it all the time. You've got stray voltage. Likewise you'll see hobbyists advising others to test the water with a meter. This in order to see if they have any. The term itself indicates as if there's electricity just wondering around in the tank, zapping all that it can. While certainly there can be electricity that is in contact with the water column, it cant go anywhere and do anything without a path. Think of the bird on a wire. It sits there all day long, not bothered by anything. Everything is perfectly fine, until it connects with another wire or some kind of ground. Then bye-bye birdie. It's the same thing within your aquarium. As long as there's no path to complete the circuit, then there's no problem. Now, add the ground probe and you have just given it a path. Will the circuit breaker trip if there's a problem? No, not always. This is because these types of devices protect by monitoring heat. Too much heat in the circuit, melts the fuse, or trips the breaker. Not that you water is cooling the circuit, don't get me wrong there, but the path that it has has enough resistance in it that it only allows a small amount of the current through....essentially. So the breaker doesn't trip. Is this scenario a hazard to you?DEFINETLY. Put your hand in the tank and give it as good or worse yet, a better path, and bye-bye- birdie. Now, A GFCI would detect this problem and have already tripped alerting you to a problem. You must eliminate the problem before the GFCI will operate again. But I digress. Anyways this current is no more stray than my favorite dog is. But this is probably the best term for this situation. As far as testing the water to determine if it exists in your DT, this can be misleading and inconclusive. I guarantee you that my Fluke digital multi meter will detect voltage on my 135. Somewhere in the neighborhood of 25 volts. With, the typical human body cannot feel. Though some may be able too. The knee jerk reaction would be stray voltage. This is possibly not so. You see I had this same scenario occur on my 65 about a year and a half ago. I was getting a little charge when contacting the tanks water if I contacted the pendant light fixtures chain which was adjacent to the tank. I took my meter, tested the water by placing one probe in the tank and one probe in the ground outlet of a receptacle. 25 volts. I began unplugging things looking for the voltage to drop as I went. And gradually the voltage would come down as each item became unplugged. It didn't take long for me to realize this was not a short that was going on with the tank. What was it
? EDDY CURRENTS. What is an Eddy current. Well, electrically speaking. This is a real and true current that is generally derived through an electrical magnetic field. But generally speaking don't have any"meat" to them. You see there is an electromagnetic field surrounding our aquariums. This is because we have powerful lights, pumps heaters, wave makers etc. all being energized around a conductive body. Essentially the electrons become attracted to this field and as it rotates in it's cycle, so do the electrons in the column. This is a fundamental process which we use mostly in the industry to generate electricity. So.... because this big field is surrounding our aquariums, my meter tells me there's something there. However, I don't believe it's real. How did I test it? Simple, I went out to my camper and got a 12volt light bulb, connected 2 wires to it. Then connected one of these two wires to a grounded outlet. The other I dropped into the tank water. If there was an actual current there, It would have easily lit the 12 volt light bulb. But it didn't. The current I was seeing ion the meter was there, because my meter didn't require any real "pressure" to detect the voltage, it saw it. But as soon as I put something in there the power would need to have some punch to operate, nadda. Eddy Currents. Now, taking that same bulb and connecting it to the chain on the pendant light, wallah, she lights up. So where was the shock coming from? The light. The problem with trying to test the water is it can be misleading., inaccurate and down right false. Now an analogue type meter, may be a little more dependable in this matter,. or an electromagnetic type meter, but I cant say from experience that it will. Most likely, i believe that they wont very accurately. Just to prove a point about the magnetic field surrounding an aquarium. Some of you may have one of those wand type voltage detectors. You know the kind you just hold up next to the wire and it lights up, beeps or does both. Try using that next to and especially right up against the glass of a "busy" aquariums. Bet it lights up most the time.
So what do you do?
You have to decide what you believe is best for you and your aquarium. IMO, installing a probe and not installing a GFCI is as bad as not doing either. While installing the GFCI's alone would be better than doing nothing. Ultimately installing the probe, insuring it is properly grounded, and installing 2 plug in type GFCI's would be the best thing too do. This again is my opinion, and I'm sure others would disagree.
Electricity and water do not mix. While pure H2O is not conductive. Most all water is. This is because of the things in the water column. Metals, DOC's, chemicals, nutrients, etc. are all what make the water conductive. Because SW aquariums have many different things dissolved in the water, with a rather high specific gravity, it is conductive. We have tons of electrical components submerged and surrounding our aquariums. All of these things have the potential to become damaged in some fashion and cause water to enter the compartments that are usually insulated from the water. Cords can also become damaged and cause a hazard. As well as water or salt even contacting these areas. Put your hand in the tank with this hazard and become grounded sufficiently and it "could" mean the end for you.
The probe.
The idea behind the probe is that it gives the current somewhere to go, should this situation arise. You wont know that it has under many situations, the electricity is basically being "drained" from the column. In circumstances where the damage to the electrical part is sufficient enough, you would likely see a breaker tripping, but it most scenarios this wont happen. There are many factors that can be involved in what will actually occur when a piece of equipment goes faulty and we can decide what will actually happen when yours does. Those who are against the probe are so mostly because it creates a path, effectively grounding the water column, and therefore touching the water then touching a piece of faulty equipment(even something in the area not associated with the tank) can cause you to be shocked. As well as those who don't believe the probe does what it is designed to do. Like most things, there are several ways to connect the probe, and many of them do not guarantee that it is correctly connected. I have seen many threads directing an individual to "connect it to the ground on the receptacle". While this in many cases should guarantee an effective ground, it does not always. The average aquarist has no way of knowing if it is, but believes that it is. Now they are under a sense of false security which makes for a hazard in itself.
How do you know?
Unfortunately, there is no sure fire way to tell by looking. The NEC requires all homes to be grounded to the Earth with an electrode. There must not be any more than 25 ohms to the ground in this connection. Basically, what this does is insure that any shorted circuit has a direct path to go to should it need to. Having a driven rod connected to the panel is one method (and the most common) of doing this. HOWEVER, it does not always guarantee this. Using a ground rod tester is one way to know how well of a ground you have. However, these are not cheap and not something you can just go to Ace and purchase. Calling a qualified electrician and having them come to your home and doing this test is an option. Be sure to ask if their shop has one and tell them what it is your wanting to do. There is something else that a homeowner could do that would most likely always guarantee the connection is good. That would be to run a second additional ground rod, 6 foot from the existing one. Then connect the two rods together with a piece of #6 copper wire. This is considered a ground rod set. It is a very effective means of accomplishing an assured low impedance ground to a home. Now if you can connect that little rod in the DT directly to these rods. You now are sure of your connection. Otherwise, you rely on your homes wiring(which should be good enough on a modern home) to make this connection to the rods. There are scenarios where this connection might not be adequate or even become degraded. Mostly these are relative to inferior wiring practices during the time the home was built and/or age of the home.
Overall, IMO, I can say that a properly connected ground probe should be a part of every aquarium. But only to be used in conjunction with a GFCI of some sorts, preferably 2 of them. I prefer to use the plug in style GFCI's. You can get these at any home improvements store. They simply plug into a receptacle, then plug you plug strips into these. If one goes bad, simply unplug it and replace it.
GFCI'S
This stands for ground fault circuit interrupter. This is a safety device which disconnects power to an appliance or other electrical equipment whenever it detects there is a problem with a short...essentially. How exactly it does this is not as important here as is why it does it. It does this to protect you from electrocution in the event that something comes in contact with water you are or could be also in contact with. These are very good at doing their job and do it quite quickly. IMO, they are a must for an aquarium. However, using only one can be a hazard for your tank mates. If it should trip while you are not around. All equipment connected to it would be off. Not a good thing with life support. I personally recommend using at least 2 of these per aquarium. Splitting all life support systems up so as to continue to maintain as much as possible should a trip occur.
Stray Voltage, shmay voltage.
This, additionally is something of great debate. You see it all the time. You've got stray voltage. Likewise you'll see hobbyists advising others to test the water with a meter. This in order to see if they have any. The term itself indicates as if there's electricity just wondering around in the tank, zapping all that it can. While certainly there can be electricity that is in contact with the water column, it cant go anywhere and do anything without a path. Think of the bird on a wire. It sits there all day long, not bothered by anything. Everything is perfectly fine, until it connects with another wire or some kind of ground. Then bye-bye birdie. It's the same thing within your aquarium. As long as there's no path to complete the circuit, then there's no problem. Now, add the ground probe and you have just given it a path. Will the circuit breaker trip if there's a problem? No, not always. This is because these types of devices protect by monitoring heat. Too much heat in the circuit, melts the fuse, or trips the breaker. Not that you water is cooling the circuit, don't get me wrong there, but the path that it has has enough resistance in it that it only allows a small amount of the current through....essentially. So the breaker doesn't trip. Is this scenario a hazard to you?DEFINETLY. Put your hand in the tank and give it as good or worse yet, a better path, and bye-bye- birdie. Now, A GFCI would detect this problem and have already tripped alerting you to a problem. You must eliminate the problem before the GFCI will operate again. But I digress. Anyways this current is no more stray than my favorite dog is. But this is probably the best term for this situation. As far as testing the water to determine if it exists in your DT, this can be misleading and inconclusive. I guarantee you that my Fluke digital multi meter will detect voltage on my 135. Somewhere in the neighborhood of 25 volts. With, the typical human body cannot feel. Though some may be able too. The knee jerk reaction would be stray voltage. This is possibly not so. You see I had this same scenario occur on my 65 about a year and a half ago. I was getting a little charge when contacting the tanks water if I contacted the pendant light fixtures chain which was adjacent to the tank. I took my meter, tested the water by placing one probe in the tank and one probe in the ground outlet of a receptacle. 25 volts. I began unplugging things looking for the voltage to drop as I went. And gradually the voltage would come down as each item became unplugged. It didn't take long for me to realize this was not a short that was going on with the tank. What was it
? EDDY CURRENTS. What is an Eddy current. Well, electrically speaking. This is a real and true current that is generally derived through an electrical magnetic field. But generally speaking don't have any"meat" to them. You see there is an electromagnetic field surrounding our aquariums. This is because we have powerful lights, pumps heaters, wave makers etc. all being energized around a conductive body. Essentially the electrons become attracted to this field and as it rotates in it's cycle, so do the electrons in the column. This is a fundamental process which we use mostly in the industry to generate electricity. So.... because this big field is surrounding our aquariums, my meter tells me there's something there. However, I don't believe it's real. How did I test it? Simple, I went out to my camper and got a 12volt light bulb, connected 2 wires to it. Then connected one of these two wires to a grounded outlet. The other I dropped into the tank water. If there was an actual current there, It would have easily lit the 12 volt light bulb. But it didn't. The current I was seeing ion the meter was there, because my meter didn't require any real "pressure" to detect the voltage, it saw it. But as soon as I put something in there the power would need to have some punch to operate, nadda. Eddy Currents. Now, taking that same bulb and connecting it to the chain on the pendant light, wallah, she lights up. So where was the shock coming from? The light. The problem with trying to test the water is it can be misleading., inaccurate and down right false. Now an analogue type meter, may be a little more dependable in this matter,. or an electromagnetic type meter, but I cant say from experience that it will. Most likely, i believe that they wont very accurately. Just to prove a point about the magnetic field surrounding an aquarium. Some of you may have one of those wand type voltage detectors. You know the kind you just hold up next to the wire and it lights up, beeps or does both. Try using that next to and especially right up against the glass of a "busy" aquariums. Bet it lights up most the time.
So what do you do?
You have to decide what you believe is best for you and your aquarium. IMO, installing a probe and not installing a GFCI is as bad as not doing either. While installing the GFCI's alone would be better than doing nothing. Ultimately installing the probe, insuring it is properly grounded, and installing 2 plug in type GFCI's would be the best thing too do. This again is my opinion, and I'm sure others would disagree.
