Stray voltage. Fact or fiction???

[elegance coral]

Can someone please post proof that "stray" voltage has any adverse effects on tank inhabitants?

It's always been a theory among some hobbyist that "stray voltage" causes problems, but it seems to be growing in popularity, with many hobbyists simply taking it as fact.

It seems that every thread I read where someone is having a problem, someone chimes in and says something like, "Stray voltage can cause that", or "Check for stray voltage".

I personally have never seen proof that stray voltage has any negative impact on tank inhabitants. If that evidence does exist, I'd love to see it.

I'm not making any claims one way or another.

Peace
EC

 

[Crabb]

The only way that could ever be "proven" would be to place the thingamajig (a proven electrical device) into saltwater (a proven electrolyte) and detect whatever current was "induced" or "shorted" (hopefully not) into the solution. For which you would need an incredibly sensitive multimeter, and an isolated mechanism so that you may detect current and not the current that you yourself might actually induce or ground into/out of the water (yes... if you're serious THAT sensitive). Problem is that in a large enough body of water the range of said electricity flow may be impeded quite rapidly. So while it may affect nearby inhabitants it may do no bother to anything beyond the range of the electrical current.

Outside of calling up Ryan at Bulk Reef Supply, I know of no one who would be willing to conduct such an experiment that might have the equipment, money, or time. I think you will be frustrated for a long time if you require such proof.

I can say that anecdotally I did have such an occurrence in my own tank with a MJ1200, however I do not know if the current was the problem, vibration, or the heat the motor put out. I noticed that when I ran the motor, the green star polyps within about 8 inches of the motor immediately started dying. Turn it off, they started to grow again, turn it back on and they started dying. Weirdest thing ever... and may quite possibly lend credence to the idea of "leaked current".

Just saying.

 

[Sounds Fishy]

I know I vaguely recall the results of a lab study on this topic ,however,I do not remember when and where ,the study happened,or,if it was based on sound scientific principle.However,I am hoping someone else may know more about it,and chime in.It is simular to what, Crabb said...
An aquarium was set up with a very slight current( as you may get in your tank from a faulty heater),with some fiddler crabs(I think)and 2 caves.The voltage was centred only in the one cave...and basically the results ended up showing that all the crabs went to the cave furthest from the source of the electricity.
I am no scientist but I always remember that study when I get a shock from my heater,or whatever ,when trying to track down the source of stray voltage when something shorts out,in saltwater (it's always something).

 

[Ryan Peters]

I had a heater blow up in my sump, it was literally fire under water. I'm gladl I had a grounding probe.

 

[Cthehentz]

I wouldn't think stray voltage would have any real affect unless it comes in contact with a ground then things get real, basically they would become part of the circuit or stray voltage. This is why you may not feel anything unless you touch something grounded aka light fixture while sticking your hand I the tank.

 

[Sk8r]

On the other hand, electricity and water and your hand make a really iffy combo. If you're getting a shock, find out why.

 

[mcgyvr]

Lets not and say that we did...

But remember kids...
GFCI or die for all submerged line powered equipment..

 

[Bluetangclan]

Whether it had any effect on life in the tank, getting shocked by putting my hand in the water had a pretty visible effect on me. A grounding probe connected to my electrical ground is standard on any tank build I do. Not like its expensive or hard to do, grounding probe is what $10 or less and installing it requires taking off the screw on an electrical plate and hooking up the probe? So easy a caveman could do it.

 

[Zalick]

I've wondered this myself. My basic understanding from college engineering was that you needed a path for the current to flow. Without a path, electricity has no effect. Which is why you can touch a hot electrical wire without getting shocked if you aren't grounded. Here is a good post from BeanAnimal. Not scientific evidence but insightful and I believe accurate.

There is no such thing as "stray voltage".

Voltage is the potential that drives current. If a voltage is present "in" the tank, it must have a path to lower potential for current to flow. Assuming that there is a path to lower potential, current will follow that path in proportion to the resistance of that (all) path(s).

Key point: Current does not take the path of least resistance, it takes ALL paths in proportion to their resistance.

So you stick a wire with high potential (voltage) in one side of the tank, and another with low potential (ground) in the other side of the tank. The water (and ihabitants) all have resistance in context to the high potential (voltage) and low potential (ground). Current will flow between the two points, using the tank water and anything else in the tank in proportion to its resistance.

There are too many variables to determine what livestock may or may not be affected by the current, as we can not easily quantify the current flow through them as their resistance is hard to calculate by itself. Add to the complexity, the fact that the position of the livestock in relation to the two points of potential (voltage and ground) and other conducting objects (salt water, rock, mineral deposits fish, coral and other organsims), and even rough estimations are almost impossible to derive.

Studies have shown that small currents (at varying voltages) can in fact be used to stimulate coral skelatal growth, and in fact the process is being used by some scientists to stimulate artificial reef growth. Likewise, it has been shown that certain levels of voltage and current can be harmful to the coral tissue and/or harmful to fish.

To repeat the key point: Current will follow ALL paths, in proportion to the resistance of the path. Trying to quantify the infinite current paths in an aquarium full of livestock is nearly impossible, so the answer to the question "Does current flow in the tank kill SPS?" is:

Maybe, maybe not. The question is too broad to answer and each specific example will be different.

No!

If the potential of the tank is 10,000 Volts becuase the HOT leg of a high voltage line falls into the tank, the fish don't care and don't know UNTIL you add the "grounding probe" and provide the VOLTAGE with a path for CURRENT to flow. At that point you kill the fish.

"grounding probes" ARE VERY misunderstood by aquarists, as are most things electrical. A grounding probe should NEVER be used unless EVERTHING in, on, or around the aquarium is plugged into a GFCI.

You can't measure "stray voltage" (It does not exist) with a multimeter connected between the tank water and ground! The results are absolutely meaningless without considering (measuring) the current.

 

[ca1ore]

The key point is above. Only use a grounding device (a probe or yourself) if you are also using GFCI devices. Personally I think 'stray voltage' is amongst the biggest red herrings in the hobby.

 

[sowellj]

Safety Issues Aside .... assuming non grounded tank

I just don't see how tank inhabitants (fish or coral) would be able to detect a voltage relative to ground, if there is not a path to ground. I am talking about the induced fields that naturally reside in tanks, not heaters or equipment malfunctioning.

For example, if I slide down a plastic slide with rubber shoes on, when I get off the slide I am sitting at different potential relative to ground. However, I cannot feel this. It isn't until I touch someone and the static discharges that I am aware of it. I know I dont have lateral lines, etc, however, in order to detect something there has to be a change and if a tank just sits at 30 volts or whatever, there is no change, it just has higher potential relative to ground.

Just my thoughts.

 

[LX20000]

The whole "stray voltage" argument is a misunderstanding of what is going on in a tank, and all around us.

We live in an environment bathed in electro magnetic radiation (sinusoidally varying electric and magnetic "waves").... cell phone towers, AM and FM radio stations, short wave radio... these are some of the items that we know about.

But there are many other devices that generate electromagnetic fields. AC motors (pumps in our tanks) are a huge source for electro magnetic fields.

Now... to understand the relationship between electromagnetic radiation and voltage, let's look at the easy example of an antenna. Physics tells us that if we place a conductor in an electromagnetic field, we can induce a current in the wire... this is how the antenna on your radio works... it's a wire sitting in the air, being bathed in radiation from 100's of sources... and in fact, if we take that antenna and connect it to a tuned circuit, and ground that circuit, we will get a voltage on the wire... a signal, and we can amplify that signal and listen to our favorite rock band. The signal would be an AC voltage/current induced in the wire by the AC electromagnetic radiation sent from the radio stations antenna.

Now, the voltage issue with aquariums comes from the following.. if you take an ohmmeter positive lead and stick it in your aquarium, while you touch the negative lead to the ground connection in an outlet... guess what you have.... an antenna. This antenna will be receptive to interacting with all the AC powered devices in your tank, especially rotating items like pumps. The electromagnetic fields being produced by devices in the tank are inducing a current (and therefore voltage) in your ohmmeter.

In fact, if you hold a lead up to a pump sitting OURSIDE the aquarium, and ground the other side, you will detect "Stray voltage" in the air.

So are your fish being exposed to "voltage" or "shocked"? No, they are being exposed to a complex set of simultaneous electromagnetic fields. They are not grounded. No current is flowing.

Should you stick a ground lead in your tank? No. The ground lead will pick up some of the electromagnetic waves propagating through the tank, and you would see a TINY current flow from your probe to ground. BUT... your fish would still be blasted by electromagnetic radiation that did not impinge on the ground lead...

Is the radiation bad? If you talked on your cellphone today, you pumped many milliwatts of electro magnetic energy through your head. You gong to worry about your fish?

Now, have a broken piece of equipment in the tank? Then the tank salt water can have a direct connection to the AC voltage, and you damn well better have a GFI.

Don't have a GFI? GET ONE TODAY. You can buy GFI's that plug into the wall, and then you plug your power strip into the device and then you plug your stuff into the power strip. Bingo, you are safe.

 

[mcgyvr]

between the bean and LX20000 information... Thats all you need..
Done..
Let this post die so it doesn't get filled up with poor information like the thousands of others...

 

[zsuman101]

I don't know if stray voltage does anything to reef inhabitants or not, but for me the reefer it blows. I have three tanks ,2 reefs and 1 frag tank . My display and frag tank have all high end equipment (mostly german and ecotech). My toss together reef has marineland, rio ,mag drive,and cheap lighting, all are on gfis, but the cheap reef zaps me all the time. It's usually the marineland heaters or the rio pumps ime. So the cheap reef is getting a Euro makeover before I die

 

[alton]

One someone says Stray Voltage I think of my days of working out in the field in retail where I would to run conduits long distances and if they ran close to MH lighting fixtures and after 500' I would end up with 5 volts on the grounding (green) wire. In our tanks we get it from motors and open lamps to the water surface. Once again no current so no shock, it is just worthless voltage. The following is one documented case of stray voltage affecting a fish, personally I have never had one of my fish act this way


(From Richard at CB pets)
We know from experience that certain fish may do poorly in tanks which have stray voltage. One example is an imperator angel we had in qt that was doing really well. Moved him out for sale and all he did was hide in the corner and would not eat. Moved him back to qt and he acted fine. Moved him back out and he quit eating. Hmmmm...so I checked for stray voltage on the tank and it was 16 volts. Added a grounding probe and he immediately started swimming around normally and ate when I fed him. So I took out the grounding probe and he immediately swam to the same corner and would not move. Put it back in and he was back to acting normal.

 

[Zalick]

(From Richard at CB pets)
We know from experience that certain fish may do poorly in tanks which have stray voltage. One example is an imperator angel we had in qt that was doing really well. Moved him out for sale and all he did was hide in the corner and would not eat. Moved him back to qt and he acted fine. Moved him back out and he quit eating. Hmmmm...so I checked for stray voltage on the tank and it was 16 volts. Added a grounding probe and he immediately started swimming around normally and ate when I fed him. So I took out the grounding probe and he immediately swam to the same corner and would not move. Put it back in and he was back to acting normal.

Seems like correlation without causation. Without a ground, the volts aren't just swirling around the tank IE the tank is not acting as a battery to store electricity. And if the potential was there, adding a grounding probe would ensure that some of those 16 volts actually passed through the fish.

At least that's my understanding.

 

[ca1ore]

Completely agree .... A load of waffle!

 

[Windy2]

I had a heater blow up in my sump, it was literally fire under water. I'm gladl I had a grounding probe.

What good did the grounding probe do?

 

[salty joe]

Lets not and say that we did...

But remember kids...
GFCI or die for all submerged line powered equipment..

Do DC pumps constitute much of a risk?

 

[mcgyvr]

Do DC pumps constitute much of a risk?

None at all provided the only thing going into the tank is low voltage DC..
All DC pumps that I am aware of have the AC/Line circuitry not anywhere near the submerged parts..
Now drop that power supply in the water and yes.. But the pumps are all low voltage and totally fine from a shock/electrocution hazard..