Voltage in tank

Discussion in 'General Discussions and Advice' started by Warr7207, 26 Oct 2008.

  1. Warr7207

    Warr7207

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    I have picked up a 185 mV (0.18 V) DC in my water column. I am battling to work out what is causing it.

    Is this harmful to the tank inmates ?
     
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  3. lIghty

    lIghty

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    how did you measure it War?
     
  4. Warr7207

    Warr7207 Thread Starter

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    With a multimeter
     
  5. goodisor

    goodisor

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    Careful there.....Dont go barefoot round the tank with your hands in or [​IMG]

    I read something a while ago about someone who had a very similar problem,they said it was an induced voltage caused by the pump motors and relative metal and magnets surrounding them.Im not too clear as to what they were saying exactly,but at the end of the day it started with a mV reading in their tank that couldn't be traced.I will try to find the article,unless someone else knows more! [​IMG]
    BTW I had a similar problem a little while ago and it turned out to be one of my powerheads which subsequntly packed up.Havent had a stray voltage again [​IMG]
     
  6. Reef Maniac

    Reef Maniac MASA Contributor

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    First suspect : pumps and power heads, second: fluorescent lights.

    Check your AC voltage, it's possibly much higher...

    Hennie
     
  7. Warr7207

    Warr7207 Thread Starter

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    Cannot get an AC reading, either the meter can't go low enough or it ain't there.

    I have tested lights and pumps individually.

    Would an inverter be a possible cause ?
     
  8. lIghty

    lIghty

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    You can't really just test like that, as its measuring the potential differance between the 2 probes in the water only, Try do a test by placing 1 probe in the water and the other on somehing that is earthed, perhaps the aluminium cover of a lighting hood (If you know its earthed)..... then you will start getting some true results....

    BUT BE CAREFULL
     
  9. lIghty

    lIghty

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    If you are running off the inverter or if using a online unit it may not have a Earth.
     
  10. Warr7207

    Warr7207 Thread Starter

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    OK, I have done it and I get a lower reading - 50 mV
     
  11. lIghty

    lIghty

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    That shouldn't be problem, in other words, if you are standing on the floor bare foot with a hand in the tank, a voltage of 50mv would pass through your body if you were made out of a conductor like copper, but you not, so only a fraction of the 50mv will pass through you. you should be safe.:thumbup:
     
  12. Dohn

    Dohn MASA Contributor

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    How could one earth the water incase there is an earth leakage. We cant put copper in the tank.
     
  13. hotdog83

    hotdog83 Clone Fish

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    IIRC titanium bicycle spokes can also work well as a tank earther. But rather find the source of the leakage and stop it, a big (electrical) current in the tank can cause problems in fish, especially tangs (lateral line erosion)
     
  14. Dohn

    Dohn MASA Contributor

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    Im thinking more in terms of the earth leakage tripping rather than getting electrocuted should there be anything wrong and you are unaware.
     
  15. Warr7207

    Warr7207 Thread Starter

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    I only picked up there was a voltage because of a wound on my hand. I cannot feel it on my other hand.

    My concern is my fish rather than myself, I know what 220VAC feel like and quick to get that sorted, it's these small voltage leakages that concern me.
     
  16. Warr7207

    Warr7207 Thread Starter

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    Make sure every electrical appliance connect to the tank has an earth connection. unfortunately this is not the norm.
     
  17. Warr7207

    Warr7207 Thread Starter

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    Totally agree, earthing tank is not a good idea.
     
  18. Dohn

    Dohn MASA Contributor

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    How do you earth the 2 pin plugs. My pumps are all 2 pins, my heater, just about everything actually.
     
  19. Warr7207

    Warr7207 Thread Starter

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    There is the exact problem.

    Some pumps you can connect the earth wire to the actual motor with some minor mods. Heaters is not something, I have any idea about.
     
  20. Dohn

    Dohn MASA Contributor

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    I think its a good idea to earth the water somehow. Doesnt have to be to the earth in the mains. Can be connected to an earth bar thats pinned in the ground or something.
     
    Last edited: 26 Oct 2008
  21. Warr7207

    Warr7207 Thread Starter

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    Problem with that, is you will never know you have a leak and the fish will take the brunt of 220 V running through the water column 24/7.

    Not good
     
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