ckyuv Posted February 12, 2014 Share Posted February 12, 2014 so lately ive been having issues with all my sps not extending polyps and slowly fading away. I had black bugs and thought that was the problem but I have done the interceptor treatments and killed them. corals are still fading, water quality is always perfect and stable. Today I purchased a bluepoint digital multi meter from the snap on dude and figured id test my tank. I turned the multimeter to 200v ac stuck the ground probe in the ground of the power outlet and the red probe in the sump. actually first I tested a glass of water and this is what I got: glass of aquarium water sitting on counter: 0.9v tank operating normal: 43v tank with everything turned off on apex: 2.7v everything off, remove temp probe: 1.8v only return: 7.1v only mp10: 4.1v 100w heater: 8.2v carbon reactor: 14.1v brs dosers:3.5v light (not touching water): 3.5v 300w heater: 12.3v skimmer: 11.8v ive been reading a lot and it seems stray voltage in the tank is obviously bad and im assuming this is why my corals are struggling or at least hoping. Seems like aquadome is the only one in town with ground probes so I will be getting one tomorrow but why would everything be adding voltage, even if its just my dosers or lights not in the water? since everything runs through the apex could this be an issue? Also the meter shows voltage without the water even being in the tank, could the meter be wrong or is this possible? Quote Link to comment Share on other sites More sharing options...
jestep Posted February 13, 2014 Share Posted February 13, 2014 I wouldn't add a grounding probe. The meter might be off a little bit, but it probably fairly close. Right now you have a voltage induced from pumps, but there's no current flow because there's no path to ground. As soon as you add a probe, there will be current flow in the tank, and anything between the equipment and the probe is going to be affected. IMO the only use for them is to protect a human from being shocked, at the expense of the tank itself, in the event of a fully shorted piece of equipment. Quote Link to comment Share on other sites More sharing options...
subsea Posted February 13, 2014 Share Posted February 13, 2014 You need to get serious about checking both neutral and ground in your house circuits. Once that is eliminated as a problem, then you need to check each piece of equipment used on your aquarium. Quote Link to comment Share on other sites More sharing options...
rchavez Posted February 13, 2014 Share Posted February 13, 2014 Do you have fish? If you had a stray voltage problem your fish would be gone. Happen to me 3yrs ago. Quote Link to comment Share on other sites More sharing options...
ckyuv Posted February 13, 2014 Author Share Posted February 13, 2014 Yep I have 3 fish and they are alive and fine Quote Link to comment Share on other sites More sharing options...
ckyuv Posted February 13, 2014 Author Share Posted February 13, 2014 I'll get a circuit tester tomorrow I know I have a bad circuit downstairs on the other side of the house but I don't think I have any probs in the kitchen. It seems funny every piece of equipment is adding voltage even my temp probe Quote Link to comment Share on other sites More sharing options...
ckyuv Posted February 17, 2014 Author Share Posted February 17, 2014 Had an electrician come out. Tested my ground for the home, replaced a few gfi outlets and a breaker but nothing pertaining to fish tank. I still show voltage. I unplugged the tank and tested each electronic individually plugged into an extension cord ran to a new gfi on the other side of the room. Same story, everything still adds voltage to the tank. I guess the next step is to buy a different multimeter tomorrow to make sure the one I got isn't on crack? Any other ideas? Quote Link to comment Share on other sites More sharing options...
Juiceman Posted February 17, 2014 Share Posted February 17, 2014 Why don't you test your meter in someone else's tank to check it? I have plenty of healthy SPS if you want a voltage comparison. Quote Link to comment Share on other sites More sharing options...
Planeden Posted February 17, 2014 Share Posted February 17, 2014 Or test it on some known source. Battery, power outlet, rubber...etc. Quote Link to comment Share on other sites More sharing options...
subsea Posted February 17, 2014 Share Posted February 17, 2014 Had an electrician come out. Tested my ground for the home, replaced a few gfi outlets and a breaker but nothing pertaining to fish tank. I still show voltage. I unplugged the tank and tested each electronic individually plugged into an extension cord ran to a new gfi on the other side of the room. Same story, everything still adds voltage to the tank. I guess the next step is to buy a different multimeter tomorrow to make sure the one I got isn't on crack? Any other ideas? Did you ask the electrician about the stray voltage in your tank? 1 Quote Link to comment Share on other sites More sharing options...
jestep Posted February 17, 2014 Share Posted February 17, 2014 How long is the extension cord? A long cord can add a lot of current to a circuit which would increase the voltage you measure in the tank on every piece of equipment. Quote Link to comment Share on other sites More sharing options...
subsea Posted February 17, 2014 Share Posted February 17, 2014 How long is the extension cord? A long cord can add a lot of current to a circuit which would increase the voltage you measure in the tank on every piece of equipment.Please explain that. In my understanding, the extended length would cause a slight voltage drop, which for each piece of equipment would cause a slight increase in amps to do the same work. If you are implying that the magnetic flux surrounding the line is generating induced voltage in the tank, good luck with measuring that. While it is true that large utility transmission lines do indeed generate substantial magnetic flux and thus induced voltage, I doubt that it would be true with the slight power consumption of reef tank equipment. Patrick Quote Link to comment Share on other sites More sharing options...
jestep Posted February 17, 2014 Share Posted February 17, 2014 Basically what you're saying. The resistance of the extension cord would increase the current load on the equipment. Same reason if you use an extension cord with a high amperage device like a hair dryer or space heater you're way more likely to trip circuit breakers or GFCI's. SInce induced voltage in a conductor is proportional to current flow, any additional load would increase induced voltage on all equipment on the same circuit. All equipment would see the additional current caused by the resistance of the cord per kirchhoff's current law. You would just have to plug the equipment into another outlet without the cord to see if there was a difference in induced voltage caused by the extension cord. I personally don't actually know if there would be a big difference. I can test on my own tank with a 100ft cord and see if there's a change. I definitely don't have this much voltage being induced in my tank as is though. Realistically I don't think it matters what the induced voltage is since there isn't going to be current flow simply as a result of measuring voltage in the tank. 1 Quote Link to comment Share on other sites More sharing options...
subsea Posted February 17, 2014 Share Posted February 17, 2014 Basically what you're saying. The resistance of the extension cord would increase the current load on the equipment. Same reason if you use an extension cord with a high amperage device like a hair dryer or space heater you're way more likely to trip circuit breakers or GFCI's. SInce induced voltage in a conductor is proportional to current flow, any additional load would increase induced voltage on all equipment on the same circuit. All equipment would see the additional current caused by the resistance of the cord per kirchhoff's current law. You would just have to plug the equipment into another outlet without the cord to see if there was a difference in induced voltage caused by the extension cord. I personally don't actually know if there would be a big difference. I can test on my own tank with a 100ft cord and see if there's a change. I definitely don't have this much voltage being induced in my tank as is though. Realistically I don't think it matters what the induced voltage is since there isn't going to be current flow simply as a result of measuring voltage in the tank. I am saying that it is an extremely small component of the equation. As an engineer, it would go to zero in the calculation. Patrick Quote Link to comment Share on other sites More sharing options...
Timfish Posted February 18, 2014 Share Posted February 18, 2014 So besides eliminating a fire hazard, it seems we've eliminated stray voltage as a problem. What's current pH, Alk, calcium and phosphates? Do you have test results from starting your tank? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.