Stray voltage in tank & cuts on finger

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debdp

Premium Member
On Pete's tank build he had mentioned feeling the stray voltage in the aquarium through a small cut on your finger/hand. I always thought it was from the salt. Today I was fishing out my dead cleaner shrimp and cut my finger on the rock. When I put my hand back in the tank I felt a sharp sting on the cut. I went to all my other tanks and felt nothing. Back into the 40 and sharp stinging. One item at a time I unplugged stuff and put my hand in the tank. The last item was my Vortech and on the next plunge no more stinging. Now it wasn't any of the equipment... not the Vortech, other pumps or heater. The small pumps & heater were all plugged into a separate outlet. The Vortech, however, was plugged into a Battery Backup that's plugged into a bad outlet. I just didn't think the Vortech could still carry the stray voltage from the bad outlet into the tank since the motor was outside. The most troubling part... I have a grounding probe in that tank. So it's either useless or I have it connected wrong. I slipped the eyelet of the probe into the screw of a wall plate.
 
That is really bizarre since glass is a very poor electrical conductor at solid temperatures. You might check all of your cords and outlets for salt creep to see if you've formed a bridge someplace that's carrying stray current back into the water.
 
@debdp wrote:
The most troubling part... I have a grounding probe in that tank. So it's either useless or I have it connected wrong. I slipped the eyelet of the probe into the screw of a wall plate. said:
Is this a 3 pronged outlet, just use your multimeter to measure the resistance from the outlets ground plug to the screw you have the grounding probe connected to. I would bet the probe (and maybe the backup unit) is not really grounded as current takes the path of least resistance, which would be through the earth ground. The box that the outlet is in may be plastic.

Cheers,
Click to expand...
 
If you have an older house (like many I have lived in...) you may have what appears to be a grounded plug. However, when you open it up you may find it does not have a real ground wire. I have seen this many times. If you have no true ground on the plug, that could be causing the issues. Just a thought for you...
 
Yes it's a 3 pronged outlet. I don't have a multimeter...and not exactly sure what it is. It's not an older home. If it makes a difference I have a 6 outlet piece plugged into the wall's original two outlets.
 
couple things

I am all but convinced that stray voltage is very leathal to cleaner shrimp - over the years I have attributed a couple mysterious deaths of cleaner shrimp that happened at the same time I found a short in a pump, light, power head, etc. I just think they are super sensitive to the stray voltage. I could be completly wrong, but your event just adds to my thoughts on the subject

I am surprized its from the Vortech unless there is some salt creep on the cord or on the outside of the tank that is providing a path for the current to enter the tank. Often times lights will cause stray voltage just but having salt creep on a plastic or wood canopy

ground probes in the sump may not provide protection for the main depending on the plumbing. or they may provide a path with some resistance that is over taken with you putting your hand in the tank thus becoming a path of lesser resistance

I agree on the older outlet concerns - the center screw may not be grounded for a couple reasons - older home when it wasn't a requirement or posibly the plug itself wasn't grounded to the common wire (green screw)

do you have GFCI outlets installed?

this may shed a whole new light on your recent events - if you disturbed the tank before using the algea stuff you may have inadvetantly created a small short (bending a cord, pulling a cord that may have cracked a seal, some water spill that provided a salt trail or current path to the tank, etc)
 
The shrimp... was trying to molt and even though he shed his old shell, he didn't pull through . I almost thought since his new shell hadn't hardened he had no protection he may have been stung by one of the large aptasias. But I don't know. The last cleaner shrimp died a week ago. I still somewhat thing it's a delayed reaction to the Algaefix as stuff is still dying off...including the bubble algae.

What is considered an old house..this one is somewhere around 15-18 years old.

All the electrical is in a closet next to the tank so no way for salt creep to get on the cords or electrical there. I need to get this outlet checked out. Before every time I touched the lights I would get the fire shocked out of me. So I took an 8 outlet power strip and moved everything except the Vortech, fan and moonlights to it. Those were plugged into the Chauvet power strip and APS backup... which were plugged into the "faulty" (I think so anyway) wall outlet I had installed. Once I moved the lights I stopped getting shocked. I added the ground probe because of this "just in case".

I normally would have attributed my huge loss to the electrical voltage issue but then it doesn't explain the same deaths in my 15 gallon tank.

As soon as I get some extra funds in I'm calling the guy who installed the outlet and have him look at it.
 
Might not be a bad idea to have someone else with a little electrical experience take a look for you. I would think many of us would be willing to take a quick look at it for you. If it is just a bad outlet, it would be nothing to change it out for you to either a new regular outlet or a GFCI either one.
 
I agree. I did document how to test for this with a meter that only costs $10 or less at Harbor Freight. http://www.reefaddicts.com/content.php/45-How-to-Test-for-Stray-Electricity

Wipe down everything. Side of the tank, the stand, nearby surfaces, the power cords, the battery backup wire (btw, those were recalled and you should get new ones from Ecotech for $2.50 each), the 6-way power strip... salt on any and all of those surfaces will allow power to travel where it normally would not.

I have a 150w DE pendant in my sump to grow frags. When it touches the PVC pipe that provides flow in the propagation section, it can conduct power. That ballast is grounded, the wire from the pendant is also three pronged. Wiping off the PVC pipe and the metal housing of the light stopped the leaking power I was able to measure, so I wipe it down every two to three months.
 
Thanks Marc. Just read through it. Even I could do that [smilie=smile.gif]

I called the guy just to see what he'd say and he was pretty upset with me for not calling sooner. Said he'll check out the wall outlet and take care of it, not to worry. So at least I can get that taken care of.

My Eheim canister filter which I was using as the "pump" from the main tank to the refugium broke last night when I tried to lock the top down. So with some new pumps sitting around for emergency I'm now totally redoing the system. Heater should be okay... hasn't been plugged in all summer.
 
question for electricity experts

Should we put the groundng probe in the display tank or in the sump (mine is in the sump). my thinking is if the pumps are in the display tank will electricity try to find a ground in the tank first before traveling through to the sump?
 
@kuyatwo wrote:
question for electricity experts Should we put the groundng probe in the display tank or in the sump (mine is in the sump). my thinking is if the pumps are in the display tank will electricity try to find a ground in the tank first before traveling through to the sump? said:
If you have only the one probe - put it where there is more opportunity for a short, for example if you sump only has one pump and a heater but the display has four power heads; every thing being equal the tank would be more suspect. But know your equipments history for example; the early hydors (#2 and 3's) are notorious for shorts. Some pumps we use as return pumps are also bad (Rio comes to mind).

Technically your whole system should be grounded by one probe as long as there is flow, but turn off the main and you may be unprotected. So. if you can run one in each that would be best. Also like I sugested the short will always take the path of least resistance so even with flow having a short in the the main and a probe in the sump may set you up for becoming the path of least resistance through your body to the floor or ground (shoes and a wet floor can make a huge difference)
Click to expand...
 
The electrician finally made it out here yesterday. I've had all the equipment already moved to other outlets for awhile now. His little light meter thing didn't show any issues when he put it inside the outlet and he goes, "I don't see anything wrong." So I said wait, let me plug in one of my lights then you can touch it, then let me know if it's okay [smilie=devil.gif] He got the **** shocked out of him. So then he went and investigated further. He found the problem, something to do with the way he wired it, but totally his fault he admitted. He redid the wiring so problem solved. But he felt so guilty he fixed another outside outlet that wasn't working for me, too. [smilie=clapping.gif] I took out the grounding probe, but I think I'll put it back in and secure it to this outlet that he just fixed which doesn't have an adapter plugged into it. So last night or I should say this morning, I totally redid the setup making it a lot more organized. I cut my finger on something yesterday and tested the tank this morning [smilie=smile.gif] no tingling on the cut. Maybe not the most scientific, but...
 
Great post. I may have to read that on a future podcast. I'm crying over here, laughing out loud.
 
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