Stray voltage, and acceptable levels

[Wiz]

Okay so long story short I am having issues with some of my coral. A lot of it is fine but some are not. Stray voltage was brought up as a possible cause. I checked with a multimeter and got a reading of 44 at the highest. Which I'm told is not good. I unplug each thing that sits in the water one by one. Each unplug dropped the level by about 2 or 3 points. One particular pump dropped it by 24 points. So I think I found the reason my voltage is so high. But this led me to wonder if each one puts in two or three volts how much is acceptable. Or normal even. If I unplug the Maxi jet that is the problem I still get a reading of about 20. Is that okay?

 

[USMC4Life]

It's probably induced current. Different from stray.

 

[Wiz]

Could you possibly elaborate on that? Is induced current okay and how would I get the reading? If they're both read the same how would you ever get a good stray voltage reading?

 

[Brew12]

Okay so long story short I am having issues with some of my coral. A lot of it is fine but some are not. Stray voltage was brought up as a possible cause. I checked with a multimeter and got a reading of 44 at the highest. Which I'm told is not good. I unplug each thing that sits in the water one by one. Each unplug dropped the level by about 2 or 3 points. One particular pump dropped it by 24 points. So I think I found the reason my voltage is so high. But this led me to wonder if each one puts in two or three volts how much is acceptable. Or normal even. If I unplug the Maxi jet that is the problem I still get a reading of about 20. Is that okay?

Unfortunately, it really isn't easy to say what is or isn't ok. It seems like 20V-30V is common for people who don't use grounding probes. Yours is on the high side. Do you use GFCI? If not, I think it is worth picking up something like this.
http://www.homedepot.com/p/Defiant-Plug-In-GFCI-Adapter-3-Wire-Grounding-30339036/203741464

You can plug your equipment into it one piece at a time to make sure it doesn't have a fault in it. It would be best to do this with a ground probe installed to ensure there is a ground path but it should work even if you don't.

The chemicals leached from the location of electrical faults can definitely cause an issue with corals and/or fish. If you have a faulted component, that could be the source of your problem.

If you don't have faulted equipment, then you can assume the voltage in your tank is induced. While not as harmful to the fish it is hard to quantify just how bad it is. I'll save that for a second post.

 

[Wiz]

There are six plugs that go into the tank. My return pump, three circulation pumps, my skimmer, and my heater. All six are plugged into a power strip which is plugged into a GFCI almost exactly like the link you put on here

 

[Brew12]

Let me start by stating that this is strictly my opinion, but it is one formed based on a strong technical and practical background with electricity.

Many people will say that induced voltage isn't harmful but faulted equipment is. I agree with that if you are talking about harmful to people. I don't agree if you are talking about fish.

People live in an environment where we are much more conductive than the air around us. The danger from electricity is in having current flowing through us, instead of the intended conductor. This current is driven by a difference in potential (Voltage). The most common event is for us to touch an energized source and a ground source at the same time. A higher voltage difference will cause more current flow. With induced voltages there isn't enough power to maintain a high enough current to hurt us. For that reason, induced voltages at these low levels are rarely harmful to people.

Birds will sit on high voltage wires below 161,ooo Volts because there is no path to ground so there is no impact on them due to the voltage. Birds will not sit on the conductor of a 500kV system. At these voltages the air becomes ionized and is conductive. This is effect is called corona. This causes a very painful pin pricking sensation because of the difference in voltages across their skin. It is also why the crazy lineman who work on high voltage systems from helicopters where chain mail suits.

Fish live in an environment where the water around them is much more conductive than they are. This means that they are always energized at the same level as the water they are living in. This is not a problem in and of itself. Seawater is not completely uniform. This means the voltage in the water isn't completely uniform, either. It will change based on temperature, salinity, chemical distribution and flow among other things. This means the fish and coral constantly have these small differences in potential all over their bodies. I believe this is why voltage in the tank leads to lateral line disease since these are voltage receptors. For fish, it doesn't matter if the voltage is induced or not. The actual voltage is real and present.

So hard to explain this in a post. Hope that made sense.

 

[USMC4Life]

Induced is when electrical equipment is producing a magnetic field that induces a DC current. If you had a faulty equipment your breaker box would tripped. And it would have been more than 40v. As long as you do not get amps you are ok.

 

[Brew12]

There are six plugs that go into the tank. My return pump, three circulation pumps, my skimmer, and my heater. All six are plugged into a power strip which is plugged into a GFCI almost exactly like the link you put on here

Excellent. Odds are you don't have a piece of faulted equipment unless your GFCI is bad. The quick and easy way to find out if your issue is voltage related is to put a ground probe in your aquarium.

 

[Pola0502ds]

Okay so long story short I am having issues with some of my coral. A lot of it is fine but some are not. Stray voltage was brought up as a possible cause. I checked with a multimeter and got a reading of 44 at the highest. Which I'm told is not good. I unplug each thing that sits in the water one by one. Each unplug dropped the level by about 2 or 3 points. One particular pump dropped it by 24 points. So I think I found the reason my voltage is so high. But this led me to wonder if each one puts in two or three volts how much is acceptable. Or normal even. If I unplug the Maxi jet that is the problem I still get a reading of about 20. Is that okay?

can you explain how you tested and used the multimeter? I would like to test my tank too.

 

[Brew12]

can you explain how you tested and used the multimeter? I would like to test my tank too.

Odds are the metal housing of your light fixture is grounded. The easiest way is to take a voltmeter set to AC Volts and touch one probe to a screw on the light fixture housing and dip the other one into the tank.

 

[Wiz]

I stuck the grounding probe into the ground on the outlet. Then put the red one in the right side of the plug and got a reading of 120 volts roughly. Then I took the red end out of the outlet and put it into the water. Got 44 volts roughly be very careful I am not suggesting you do anything. LOL

can you explain how you tested and used the multimeter? I would like to test my tank too.

 

[Wiz]

So why then do five of the six put out between 2 and 4 volts and one puts out roughly 24 volts?

Induced is when electrical equipment is producing a magnetic field that induces a DC current. If you had a faulty equipment your breaker box would tripped. And it would have been more than 40v. As long as you do not get amps you are ok.

 

[Brew12]

So why then do five of the six put out between 2 and 4 volts and one puts out roughly 24 volts?

Voltage is induced in our aquarium water through the expansion and collapsing of magnetic fields from our AC distribution system. A weak form of induction would be from cords run inside our tanks or right along the outside edge. The longer the cord run in proximity to the tank, the higher the voltage induced. The strongest source of induced voltages is from motors. The motor windings to create magnetic fields to generate motion. If these windings aren't shielded they will be a significant source of induced voltages. The bigger the motor the more potential for induction.

 

[Wiz]

So wierd. Retested voltage at 1030 last night. Only difference was lights were off. Got a reading of 9v. I thought it had to be wrong. Turned the lights on and tested again. It dropped to 8.6!
Trying to make sensense of it I thought maybe the heater because it's intermittent. I turned it on and tested. Still 8.6.
Tested this morning and it's 6v!

So 44v around 1pm
9v at 1030
6v at 9am.

Um..... I'm no electrician but how is this possible? ?

 

[Brew12]

Just saw this on your other thread and answered.

https://www.reef2reef.com/threads/popcorn-ceiling-killing-my-hard-coral.291201/page-9#post-3552043

 

[Wiz]

Yeah the other post transition from the ceiling to the electric. I figured the Stray voltage was better in its own post. But I did not want to leave everyone hanging either. LOL and thank you

 

[Brew12]

Yeah the other post transition from the ceiling to the electric. I figured the Stray voltage was better in its own post. But I did not want to leave everyone hanging either. LOL and thank you

I agree, which is why I also posted here. This is probably a better place for this part of the conversation.

 

[USMC4Life]

So wierd. Retested voltage at 1030 last night. Only difference was lights were off. Got a reading of 9v. I thought it had to be wrong. Turned the lights on and tested again. It dropped to 8.6!
Trying to make sensense of it I thought maybe the heater because it's intermittent. I turned it on and tested. Still 8.6.
Tested this morning and it's 6v!

So 44v around 1pm
9v at 1030
6v at 9am.

Um..... I'm no electrician but how is this possible? ?

You could have some piece of gear that is feeding back some magnetic field depending on the combination of what's running and if there is some magnetic oscillation it can increase the induced DC current or decrease it depending on its frequency.

Think about it this way, if you have a coil and you move a magnet inside it and depending how fast or slow you move it that will correlate with electrical output.

 

[Wiz]

I've been measuring it periodically for the past two days. It has reached as high as 82 volts. This morning when I left it was sitting at 1 volt. Both my heater and my maxi jet 1200 we're putting out too much so I replaced those. But I still have the fluctuation

 

[USMC4Life]

What do you use to measure the voltage and have you measured the amps?

Also did you see if it is AC or DC.

Do you have anything on a timer?

You can shut everything off and turn one thing at a time and record the findings then what you can also do is run one thing at a time to narrow down what gear is giving you the majority of the induced current. And by comparing the tow methods you can also figure out if it's a combination of gear that is causing the magnetic oscillation that is giving you the voltage spikes.