How do I use this multimeter to measure stray voltage in my tank?

xdestry · 06/30/2014, 02:38 AM

Hi guys, a few days ago I had a cut on my finger and i put it into the tank and felt a shock, leading me to believe i have quite a bit of stray voltage in the tank. Anyway I bought this multimeter today and was wondering if you guys can tell me how to use it to measure the voltage.

Right now from reading other sources online I think i need to put the red plug in the vma slot, black in com. Switch the switch two to the left to 200 in the V section. Then insert black into the big prong hole in an outlet somewhere and the red in the tank. I wanted to make sure I got this right before attempting.

Thanks for any help you can provide

xdestry · 06/30/2014, 04:24 AM

I went ahead and measured it and think going to the 200 on the left was wrong, and it needed to be to the 200 on the right instead. Anyways heres the voltage readings

In return pump compartment in sump 0.3
Refugium compartment 2.5
Skimmer/heater compartment 3.2

Display tank 10

These numbers seem low enough that I don't have to worry right? I was kind of shocked at how much it hurt when I put my finger in though thought it would be more. One question I have though is why is the voltage reading in the DT so much higher than in the sump? I have no electronics in the DT except for the two vortech wetsides. When I start unplugging things in the sump the readings drop a bit in both the sump and DT, but in the DT about a factor of 4x more than the sump readings. Does it have something to do with the bigger water volume in the DT?

Hudzon · 06/30/2014, 07:32 AM

to make sure you are measuring the voltage correctly just push both the red and black lead into an outlet and it should be 110-120v
For the readding in your display, try turning off your lights and fans, and checking if they are close enough they could be putting off induced voltage

FishInABarrel · 06/30/2014, 07:38 AM

You want AC voltage, which I believe is to the right of the off position. I can't read it on your pic but that's how it is on my multi-meter. AC to the right, DC to the left.

whiteshark · 06/30/2014, 07:48 AM

I would guess you don't get an electrical shock. Just a "sting" from the salt water getting in your cut. I've made the same mistake. Any little cut when dipped in saltwater stings like hell.

06/30/2014, 02:38 AM	#1
xdestry SPS Addict Join Date: May 2014 Location: Pasadena, CA Posts: 662	How do I use this multimeter to measure stray voltage in my tank? Hi guys, a few days ago I had a cut on my finger and i put it into the tank and felt a shock, leading me to believe i have quite a bit of stray voltage in the tank. Anyway I bought this multimeter today and was wondering if you guys can tell me how to use it to measure the voltage. Right now from reading other sources online I think i need to put the red plug in the vma slot, black in com. Switch the switch two to the left to 200 in the V section. Then insert black into the big prong hole in an outlet somewhere and the red in the tank. I wanted to make sure I got this right before attempting. Thanks for any help you can provide

06/30/2014, 07:48 AM	#5
whiteshark Registered Member Join Date: Mar 2006 Location: Bethlehem, PA Posts: 3,024	I would guess you don't get an electrical shock. Just a "sting" from the salt water getting in your cut. I've made the same mistake. Any little cut when dipped in saltwater stings like hell. __________________ Deep Blue 60 gallon cube: Setup in progress.

06/30/2014, 04:24 AM	#2
xdestry SPS Addict Join Date: May 2014 Location: Pasadena, CA Posts: 662	I went ahead and measured it and think going to the 200 on the left was wrong, and it needed to be to the 200 on the right instead. Anyways heres the voltage readings In return pump compartment in sump 0.3 Refugium compartment 2.5 Skimmer/heater compartment 3.2 Display tank 10 These numbers seem low enough that I don't have to worry right? I was kind of shocked at how much it hurt when I put my finger in though thought it would be more. One question I have though is why is the voltage reading in the DT so much higher than in the sump? I have no electronics in the DT except for the two vortech wetsides. When I start unplugging things in the sump the readings drop a bit in both the sump and DT, but in the DT about a factor of 4x more than the sump readings. Does it have something to do with the bigger water volume in the DT?

06/30/2014, 07:32 AM	#3
Hudzon Registered Member Join Date: Oct 2009 Posts: 267	to make sure you are measuring the voltage correctly just push both the red and black lead into an outlet and it should be 110-120v For the readding in your display, try turning off your lights and fans, and checking if they are close enough they could be putting off induced voltage

06/30/2014, 07:38 AM	#4
FishInABarrel Registered Member Join Date: Feb 2014 Location: Grande Prairie, Alberta Posts: 275	You want AC voltage, which I believe is to the right of the off position. I can't read it on your pic but that's how it is on my multi-meter. AC to the right, DC to the left.