DIY - How to test for Stray Voltage in your Aquarium
- Thread starter DocP
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I was recently messing around with my leds above the tank. I unplugged the rca jack from one of the 9v wall warts and didnt notice that it had fallen into the tank.
I noticed my clam opening and closing, and assumed it was reacting to the change in light. Anyway, it was in the tank about 10 min total. After the incident i lost all of my xenia. Every bit of it melted away within the next 24 hrs. No other coral losses and no fish losses.
This leads me to assume that certain species maybe more sensitive to electrical current just as some are sensitive to certain water params.
I noticed my clam opening and closing, and assumed it was reacting to the change in light. Anyway, it was in the tank about 10 min total. After the incident i lost all of my xenia. Every bit of it melted away within the next 24 hrs. No other coral losses and no fish losses.
This leads me to assume that certain species maybe more sensitive to electrical current just as some are sensitive to certain water params.
DIY - How to test for Stray Voltage in your Aquarium
Recently I got home from work and took a shower; the next day I woke up with a cold. This leads me assume that taking a shower after work causes the common cold.
That sounds pretty ridiculous doesn't it ? But it's the exact same thing as your example. Correlation is NOT causation. What you said happened simply can not cause what you are describing.
Electricity doesn't work that way. If you had put a positive lead on one end of the tank and a negative on the other end, then MAYBE you could look at that as a cause. But even then, 9v at maybe 500ma would do nothing. Even if you were putting through much higher voltages and current, you also have to think about conductivity; if the water is more conductive than coral tissue, current will flow around, rather than through.
Recently I got home from work and took a shower; the next day I woke up with a cold. This leads me assume that taking a shower after work causes the common cold.
That sounds pretty ridiculous doesn't it ? But it's the exact same thing as your example. Correlation is NOT causation. What you said happened simply can not cause what you are describing.
Electricity doesn't work that way. If you had put a positive lead on one end of the tank and a negative on the other end, then MAYBE you could look at that as a cause. But even then, 9v at maybe 500ma would do nothing. Even if you were putting through much higher voltages and current, you also have to think about conductivity; if the water is more conductive than coral tissue, current will flow around, rather than through.
I think its a pretty big coincidence...mature tank with full large colonies of coral including xenia. Nothing else happened to the tank at that time, no additives, no water changes, heaters both intact. Temp, ph, alk, salinity all remained constant. I really cant think of.anything that could cause all of the xenia to literally melt and dissolve within a 24 hour period. Anyone willing to test this? Maybe ill set up a small tank with a sample of xenia and see what happens. Ill post when done....
uncleof6
Active member
Ok, probably a coincidence.
You dropped an "rca" jack coming from a wall wart, into the tank. The wall wart produces 9 volts. (it was probably a little less than that, as wall warts are not the most efficient devices around.)The voltages we are discussing are between 12 and 40 volts. ( 9 volts is close enough.) The problem is, we are discussing VAC (volts alternating current.) What comes out of the wall wart is VDC (volts direct current.)
DC is not what the concern here is, it is AC. With the rca connector from the wall wart, the center post is the +, and the "outside" is the ground. Where the dc current went, if it went anywhere at all, was from the center post, cross the short distance to the ground portion of the connector, and the only reason the wall wart did not burn up, is the resistance of the salt water.... the current did not go "running around" in your tank.
Even with faults in ac motors, (most often they are high resistance line cord faults, because they often don't use the best cords for the job...) the current flow will remain local to the faulty pump/cord (path of least resistance is to the ground of the pump, or the neutral, if either path exists.) The current would remain local to the pump, or it can impress a voltage in the tank, if a path to ground is not present.
From a master electrician's POV I gotta speak up here, as I am reading some bad advice.
I would consider any voltage to be harmful, as far as measuring current, you would need an amp meter and probes, if there is current present it will kill you. -You only need milliamperes to stop your heart.
As far as voltage goes, yes it's bad, yes it can hurt you, and for the record, voltage below 49volts or less is considered Extra Low Voltage, it doesn't hurt us because our skin is thick enough to have enough resistance to stop it. I highly doubt our fish and coral have skin thick enough to do the same. Perfect example: ever lick the top of a 9v battery? Our tongue doesn't have enough resistance to stop the voltage -so it stings, just think of your poor tang swimming into the path of current. I have also heard sharks can sense low voltage fields from 100's of miles away. Maybe our fish are equally as sensitive to it as well.
A ounce of prevention:
-Keep cords and sockets away from water
- use protection; GFI receptacles and ground probes, it can save your life
- wire everything with drip loops -so the cord hangs below the receptacle and the water drips away before it reaches the plug.
-Never unplug a cord with wet hands
-try to put pumps and other equipment you regularly unplug/plug on switches so you de-energize before unplugging.
-Tunzi makes a voltage/ current alarm, you plug it in to your receptacle, and drop a prob in the water, if it measures a different in energy potential it sounds an alarm to keep you from putting your hands in the water and killing yourself.
Anyone who thinks electricity and water (salt water in particular) mix well, doesn't understand electricity.
I would consider any voltage to be harmful, as far as measuring current, you would need an amp meter and probes, if there is current present it will kill you. -You only need milliamperes to stop your heart.
As far as voltage goes, yes it's bad, yes it can hurt you, and for the record, voltage below 49volts or less is considered Extra Low Voltage, it doesn't hurt us because our skin is thick enough to have enough resistance to stop it. I highly doubt our fish and coral have skin thick enough to do the same. Perfect example: ever lick the top of a 9v battery? Our tongue doesn't have enough resistance to stop the voltage -so it stings, just think of your poor tang swimming into the path of current. I have also heard sharks can sense low voltage fields from 100's of miles away. Maybe our fish are equally as sensitive to it as well.
A ounce of prevention:
-Keep cords and sockets away from water
- use protection; GFI receptacles and ground probes, it can save your life
- wire everything with drip loops -so the cord hangs below the receptacle and the water drips away before it reaches the plug.
-Never unplug a cord with wet hands
-try to put pumps and other equipment you regularly unplug/plug on switches so you de-energize before unplugging.
-Tunzi makes a voltage/ current alarm, you plug it in to your receptacle, and drop a prob in the water, if it measures a different in energy potential it sounds an alarm to keep you from putting your hands in the water and killing yourself.
Anyone who thinks electricity and water (salt water in particular) mix well, doesn't understand electricity.
alb_56
New member
Just some quick learning questions here. When we test our water which hole do we put the black probe into on a three hole socket, and which hole for a two hole socket? Is a "wall wart" just a general term referring to a power supply that is bulky and converts power from AC to DC? Sorry if this info is somewhere else, just seems like you guys know exactly what you are talking about so I thought I would ask, thanks.
uncleof6
Active member
WEEEEELLLLLLLL.....ok I won't say it.
Does not matter what color the probe is, rather one goes in the "hot" and the other goes in "ground" (the rounded hole at the bottom.) But even if you put one probe in the "hot" and the other in "neutral" the reading will be the same (120 volts) as the neutral is bonded to the ground bus in the service panel.
With a 240 volt system it is a bit different. From hot to hot, the voltage will be 240volts. From one leg to ground the voltage will be 120 volts.
A wall wart is a "black box," that plugs directly into a recepticle, containing a step down transformer (comes first; lowers the voltage,) a diode bridge that changes the current from AC to DC, and some capacitors for filtering (cleaning up,) the DC current. The quality of the "wall wart" depends on how well the DC current is filtered, and its current limitations. For comparison, power supplies for power amps, are judged in the same manner.
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Reefvet
New member
And test those GFI's. I recently discovered one in my kitchen was installed without a ground. I plugged in a Tripp Lite power strip and it's ground fault light came on. I turned off the breaker and opened the outlet to find a GFI that was useless as installed. Done by a master electrician who won't be working for me again.
uncleof6
Active member
Contrary to popular myth
, the operation of a GFCI has nothing to do with whether or not the recepticle is grounded. The GFCI monitors the current flow in the hot, and the neutral. If there is a difference in current flow, current must be going somewhere else. The GFCI does not care where it is going, it simply 'sees' that out is less than in and trips. According to NEC, there is no need to ground a GFCI, if there is no equipment grounding conductor. The GFCI must be labled: No Equipment Ground. The GFCI will function properly, and will trip in the case of a ground fault downline from the GFCI.
IF there is an equipment ground in the box, and it is not hooked up, well...ok, the electrician got lazy or did not see it. However, the GFCI will work as it is supposed to. The equipment ground is present to protect equipment, the GFCI is what protects you.
So now we have two different answers from two different experts(assuming uncleof6 is an expert).
OK, what is the deal??? I'm on the fence as to what is correct, ground with gfi or not. BTW, I am NOT an expert.
Thunderfan
New member
I'll put my two cents in as an electrical contactor with 20+ years experience. Uncle is correct on saying that the ground on a gfci has nothing to do with the protection of the gfci. It operates by sensing between hot and neutral. The ground is nothing more than an equipment ground. That being said it is important on some equipment to give voltage a path that isn't you. The only protection a ground probe may do is discharge static electricity. Someone Mentone electronics guys wearing bracelets with grounds that get attached before working. The only purpose of them doing that is to discharge static electricity. Static and electronics do not go well together.
HECS makes some good points but is not correct in stone of them. Voltage is not the problem as others have said. It's the amperage that is dangerous. As a master ejector surely he has connected wires while they are hot. If not, that's OK some haven't but I have many times. The trick is not to be grounded. I have connected services to houses many times while the primary was live but, in no way was I grounded. Electricity will always take the path to least resistance to ground ALWAYS. If you are not that path it will not hurt you. The reason why touching your tongue to a battery gives you a shock is because you are touching both positive and negative at the same time and with the moisture in your tongue which is a great conductor you are completing the circuit. If your water is grounded then you are completing that circuit. In house plumbing they use ground probes but not for what people are thinking here. They use them to help prevent scale buildup in certain systems. Maybe somebody from that industry thought they could make some bucks selling them to people in this hobby.
HECS makes some good points but is not correct in stone of them. Voltage is not the problem as others have said. It's the amperage that is dangerous. As a master ejector surely he has connected wires while they are hot. If not, that's OK some haven't but I have many times. The trick is not to be grounded. I have connected services to houses many times while the primary was live but, in no way was I grounded. Electricity will always take the path to least resistance to ground ALWAYS. If you are not that path it will not hurt you. The reason why touching your tongue to a battery gives you a shock is because you are touching both positive and negative at the same time and with the moisture in your tongue which is a great conductor you are completing the circuit. If your water is grounded then you are completing that circuit. In house plumbing they use ground probes but not for what people are thinking here. They use them to help prevent scale buildup in certain systems. Maybe somebody from that industry thought they could make some bucks selling them to people in this hobby.
Nor_Cal_Guy
New member
In my experince as a tankless water heater technician, the electric scale prevention devices are not effective in preventing scale build up. Water treatment is necessary.
rfgonzo
New member
Let me make sure I get this right. Are you saying that if you have a ground probe in your tank and you put 1 hand inside the tank you now completed the circuit? (If you have a problem) If yes, does this mean you are better off without the ground probe? and now with no GP if you put 1 hand in the tank your not grounded so you should be safe?
uncleof6
Active member
Every discussion of "grounding probes" is going to be a debate. We have a collection of professionals in the electrical field, ranging from journeyman all the way up to engineers. Every time it comes up, the lines will form. And in the end, because the subject cannot be covered sufficiently without many dying of boredom, folks walk away with no notion of what is correct and what is incorrect.
The best way to take a superficial look at it, without the involved technical aspects is "grounding probes" are sold based on marketing hype. "Stray voltage is present in all tanks" which is conditionally true (see further down; ) following this comes the "stray voltage is dangerous..." with varying degrees of nonsense following.
The question you have to ask is: are you going to go and buy "reef safe ich killer?" that either does not work, or causes more harm than good? Using this example, there is plenty of scholarly information concerning the issue and it would be fairly easy to determine it is marketing hype, and nothing more.
A more reality based example would be "Reef Safe, non-toxic, cycling aid, provides the beneficial bacteria in half the time, no system should be started without this miracle solution." This one would be a bit more difficult to get through, and very much preys on the "supposed" ignorance of the hobbyist. Though they should be very offended by the insult to their intelligence, many will go out and buy the stuff. Their initial cycle will still take 4 - 8 weeks, and the marketer walks away with the money. IMO there should be a law prohibiting the profit by taking advantage of what they hope the hobbyist does not know.
“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.” This one has created a debate that will last for a century.
First there is no such thing as stray voltage. Second voltage is not a problem, it never has been, and never will be. Do you want to waste 20 bucks on something that is being sold based solely on marketing hype that contains a small amount of truth, and according to some (many?) causes a larger issue than the one it is supposed to mitigate? Who is right? Who is wrong? Who is qualified to answer the question? Who is not?
You have the "Master Electricians" that say it is mandatory, on the next page you have the "Engineers" saying it is snake oil, and causes more harm that good. (Calling it the "work of the devil" is a direct quote from an EE here on RC.) On a forum, it can go either way however. To say who is more qualified would be presumptuous, as there are a couple tracks that can be followed to get to Master Electrician, and one of them involves an engineering degree. So I am not going to try to address your dilemma over that.
The only article that actually takes a reality based look at this topic, was written by an engineering professor from Georgia Institute of Technology. It can be found here: (It was originally hosted on the Georgia Tech servers, however the links are dead. (http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GroundingProbes.html )
http://angel-strike.com/aquarium/GroundingProbes.html
Hopefully, that can answer your questions.
The only errata I would like to see attached to the article, concerns the bird on the wire. The main point is valid (the bird does not get fried,) however current does flow through the bird—a very high resistance parallel path, in which the current is far below the threshold of perception, and very far below lethal.
Beyond that, the decision is yours to make. It is not a "no brainer" topic. I will add that the leading cause of loss associated with aquariums is fire, not electrocution, followed by tripping over extension cords. (Arson.org, and NFPA.) Electrical safety is a matter of common sense, not devices alone; the potential for shock is present and does deserve consideration however.
uncleof6
Active member
No, the circuit is already complete, you create a branch circuit if you are grounded or touching something that is hot. Yes you are. No you won't be.
There are three common sense items here.
The first is don't stick bare hands in the tank. There is more than one reason to follow that "rule." Should not put bare hands in the tank for biological/chemical reasons, not that the tank will harm you, rather the other way around, your hand is a potential threat to the tank water and critters.
Second: If you need to move electrical equipment around: turn the power off. No but, what... turn the power off.
Third: If you violate rule number 1 and 2, and you think you get a shock, don't stick your hand back in to see if you really did get a shock.
Finally, avoid problems by maintaining your electrical equipment.
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Even though you're absolutely, 100% correct, people are going to ignore you because you've used too many words they don't understand, and that elicits suspicion. "Why is this guy making such a complex explanation, when the salesman for the grounding probe made such a simple one? The salesman must be right." These are the same kind of people who believe in things like cellphones causing cancer, overhead power lines causing cancer, microwaves causing cancer, wind farms causing cancer, even though reams and reams of evidence exists to the contrary.
At the end of the day, people have already made their mind up whether they'll believe you or not. You are much, much better off conserving your energy for your own pursuits and letting the dimmer folk pursue all the snake-oil fixes they can find. When the chips are down, you're happy and they're too stupid to realise they've been ripped off. And the salesman is laughing with their money.
