Stray Voltage revisited...

[brewmaster15]

Hi all,

I know this has come up before but I thought I would ask again. Is there a such thing as stray voltage in a fish tank and can it harm the fish?

I was under the impression that it doesn't really exist, because The fish is not really grounded . I was always amazed when a heater broke and I got shocked that the fish were fine. I think alot of people have the same feeling that stray voltage isn't real in a tank.

My question is this then.. while reading an old fish book on collection techniques I was reminded of fish shocker... 2 probes placed in front of a boat. ...fish swimming between the probes are stunned..if they touch a probe...killed. So how can one reconcile that to thoughts on stray voltage. Sorry if I am over looking something obvious here.

-al

[ronrca]

Lol! Your bad Al. ;) I dont have to go into to much detail as we've had this subject before but questions are a good thing. I suppose my quarrel is mainly terminology and what definies 'stray' voltage.


I was always amazed when a heater broke and I got shocked that the fish were fine. I think alot of people have the same feeling that stray voltage isn't real in a tank.

Broken or faulty equipment does not classify as 'stray' voltage as there is a reason for this voltage to be present in the water. If you remember the definiation of 'stray', basicly meaning 'lost' or wandering without reason, this voltage certainly is not lost.


My question is this then.. while reading an old fish book on collection techniques I was reminded of fish shocker... 2 probes placed in front of a boat. ...fish swimming between the probes are stunned..if they touch a probe...killed.

I would call this cheating rather than fishing imo. lol! Water is a good conductor of electricity and when there is a complete path for electricity to flow, it will. This is the case in the fishing technique. Again, this is not 'stray' voltage. Its like sticking the + and the - of a battery in water! In a lake however, you need to calculate certain factors to ensure the probes are spaced at the correct distance from one another to make it work. If they are too far apart, nothing will happen unless you add more power to overcome the resistance of water. Does that make sense?


I was under the impression that it doesn't really exist,
Actually stray voltage does exist and is beleive it or not, natural in certain situations. I do have articles on that btw. However, in a tank of water, if you have or experience 'stray' voltage, better check your equipment as it very likely may be faulty.

[Anonapersona]

I find myself wondering about this, because discus that are from either black water which is dark and clear and tea colored, or white water, which is milky and opaque and caffe au lait colored, must depend on electrical signals to some extent to recognize other discus, particularly for mating. Isn't it likely that the "shaking" we see as pairs form is generating an electirical signal? This would be sensed even when visual contact was lessened.

Not that I have any answers, it is just that it seems to me that this is or could be an important item in how these fish act toward mates or potential mates. Maybe stray or rather excess voltage, could interfere with mating signals. Or even vibrations from filters and pumps and lights?

[ronrca]

I find myself wondering about this, because discus that are from either black water which is dark and clear and tea colored, or white water, which is milky and opaque and caffe au lait colored, must depend on electrical signals to some extent to recognize other discus, particularly for mating.
Very good thoughts and I would love to visit the amazon to do some research. LOL! I wish! In actual fact, the purer the water, the less conductive. Pure water does not conduct electricity very well or at all. Therefore, being that the natural waters seem to be 'cleaner/purer', they may be less prone to 'stray' voltages. I dont either have all the answers and Im sure that electricity in natural does have an enormous impact.

However, in our fish tanks, the electrical equipment the we are utilizing, such as submersible pumps, heaters, etc, in relation to any significate voltage generation are too small to really make an impact. We are talking about 120V and perhaps 1-3amps. The electromagnetic field (EMF) when calculated from the equipment is so small that it is not relavant (compare this to 69kV overhead power line where at night you can see a fluorescent tube glow when standing beneath it).

Anyways, Im starting to babble now. :p

[Anonapersona]

In actual fact, the purer the water, the less conductive. Pure water does not conduct electricity very well or at all. Therefore, being that the natural waters seem to be 'cleaner/purer', they may be less prone to 'stray' voltages. I dont either have all the answers and I'm sure that electricity in natural does have an enormous impact.

Oh, of course, very good point about the conductivity -- then electrical signals would be much less effective. So much for that theory...


However, in our fish tanks, the electrical equipment the we are utilizing, such as submersible pumps, heaters, etc, in relation to any significate voltage generation are too small to really make an impact. We are talking about 120V and perhaps 1-3amps. The electromagnetic field (EMF) when calculated from the equipment is so small that it is not relavant (compare this to 69kV overhead power line where at night you can see a fluorescent tube glow when standing beneath it).

Anyways, Im starting to babble now. :p

No, no, this is where it gets interesting!!

[brewmaster15]

ron,
one thing to note on the shocker was it uses a 220volt generator, and studies showed that 240 interruptions per minute was most effective.

Additionally on the note of electric fields..I am not sure the shaking would generate an electric signal, though it might. If my limited understanding of this is accurate that would depend on the conductivity of the water which is very low in the amazon. As a side note the fish shocker I mentioned depended on a miminum water hardness of 25ppm..or the field would have been two small between the shocker probes (positioned at what looks like 6 foot a part.)

on the fish signaling question I have witnessed in my tanks the discus responded to the shape of a discus as a shadow thru painted tanks, so it may be the actual shake that does the trick, possibly aided by the blues and reds which get brighter during breeding on wilds and may attract better than a drab fish would...speculation on my part having never been there :)
yet
-al

[tpl*co]

Wow! Leave it to Al to get a interesting and provocative thread going! I don't know much about the electricity thing, but remember about the previous hormone vs pheramone post? Maybe when a discus shakes it is releasing pheramones? (OK, I probably have more than one spelling error, no coffee yet, LOL!)

[ronrca]

ron,
one thing to note on the shocker was it uses a 220volt generator, and studies showed that 240 interruptions per minute was most effective.

Do you know whether that is AC or DC by any chance?


Additionally on the note of electric fields..I am not sure the shaking would generate an electric signal, though it might.
Shaking doesnt generate anything electricly. In order to generate voltage, by definition, a conductor must pass thru a magnetic field. Therefore electrical equipment vibrants or discus shaking will not generate any voltage.

Perhaps that we are on the this topic, we could go into some of the basic fundamentals of electricity and the best place to start is at the very beginning, at the very primary state of matter, the atom (give me a couple hours to put something together given someone is interested though).

[ronrca]

The very basic fundamentals of Electricity

In the beginning, there was an atom! We know that all matter is made up of atoms and that atoms consist of electrons, protons and neutrons. Most matter is in an uncharged state meaning that there are an equal number of positive (protons) and negative (electrons) charges. Or in other words there is no difference in the number of positive and negative charges.

However, there are a number of ways or methods to change this neutral state. To name a few, these are friction, heat, photoelectricity, battery, moving a conductor thru a magnetic field, etc.

There are two conventions when it comes to explaining the ‘flow’ of charges of an atom (or also simply called current flow). They are:

- the conventional current flow, which is positive to negative flow
- the electron current flow, which is negative to positive flow.

The most common convention is the last one where the electrons are the ones that are flowing or moving. It is important to know this as this will help understand how matter can change from neutral states. Lets take the first method, friction, as an example. Remember our high school science class where the teacher used a rod and some fur and rubbed them together. What happened to the rod? It produced a shock because the electrons transferred from the fur to the rod. The rod now has become negatively charged because it has more electrons than protons.

Lets talk about the last method now as we are more familiar with these ‘magnetic’ fields in our fish tanks from electrical equipment such as pumps, heaters, lights, etc. First, there is a close relationship between the flow of electrons and magnetism. In other words, magnetism is due to the flow of electrons in the atoms (I would like to point out this flow. Without flow, there is no magnetism). This magnetism is called an electromagnetic field. Therefore, simply stated, if there is current flow, there is an electromagnetic field generated around the conductor. If we remember when we played with magnets, the closer the magnets came to one another, the stronger the ‘pull’ or force. The same thing with electromagnetic fields; the closer to the conductor, the stronger the force. That, however, in itself does not influence anything the same as a magnet alone by itself.

There are electrical wires everywhere we are (unless tenting). In our house, for example, we utilize 120/240V. There is not enough power generated for the wire to affect the air that is around the wire. We all have heard of power jumping across an air gap (arcing) which is extremely dangerous. In these cases, there is enough power available to ionize the air and allow the transfer of electrons thru the air. This can happen under certain circumstances however the main point being that there must enough power available and we are talking kV in these situations.

Now, water is a much better conductor than air so what happens when you put a wire into water? Lets continue with our discussion of electromagnetic fields first. We have water, which is a conductor, flowing thru an electromagnetic field. In electrical terms, when we have a conductor moving thru a field, electromagnetic or even just a magnetic field, a voltage will be induced into the conductor moving thru the magnetic field. This is called electromagnetic induction and the voltage produced is called induced voltage. Now we are getting closer to thread topic of stray voltage. The amount of voltage that is induced into this conductor moving thru the magnetic field is dependant on the following factors:

- the amount of magnetic lines of force
- the rate at which the conductor moves thru the magnetic field
- the number of turns of wire in the winding of the conductor

An important factor now is understanding that in the presence of voltage, it is not necessary that there is electron flow. Why? If we remember from the beginning that electrons flow from negative to positive therefore a complete circuit is required for electrons to flow. No complete circuit, no electron flow. If there is a complete circuit, the amount of electron flow is determined by:

- the resistance of the conductor passing thru the magnet field
- the area and length of the conductor in contact with the magnet field

Now, if we apply this to our fish tanks again. First, the amount of magnetic lines of force. Again, we are talking about 120V and we can quickly establish that there is not much of an electromagnetic field being generated from this voltage therefore the strength of the electromagnetic field will not be very strong.

Second, the rate at which the conductor moves thru the magnetic field. We are talking still about our fish tanks and water is acting as the conductor therefore at what rate do the water atoms move thru the magnetic field? Hard to tell! The rate will vary quite a bit.

And thirdly, the number of turns of wire in the winding of the conductor or in our case, the number of atoms perhaps. Again, the same as above, hard to tell how many atoms and even how many atoms are passing thru this field.

So, in conclusion then, given the above, under normal circumstances where there is no faulty equipment or wires, the magnetic field produced by the flow of electrons will be very small that any voltage that may be induced will again be very small. Therefore, under normal circumstances, there will not be any stray or induced voltage.

Enough for now I guess since most have probably gotten bored by the second paragraph.

I hth! ;)

[Anonapersona]

And yet, I read about fish that attack prey (or children) when attracted by the electrical signals produced by muscles when working. Not all electricity comes through wall outlets!

[ronrca]

Yes, the nervous system has the ability to generate and conduct electrical signals. Isnt the human body amazing? Without our neurons sending current to each other, what would we be, what could we do? This is another cool topic but Im not even close to knowledge in the biological stuff however the basic concept stays the same, electrons flowing. However, I don’t think that the electrical pulses that we or animals generate inside our bodies have enough power to affect the outside environment enough to induce sufficient voltage of any concern. That is really amazing the certain animals can detect these pulses though.

I wonder if that is why some people just irk me just be coming near me. LOL!