what to use for a ground probe?
- Thread starter SmyrnaReefer
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Ground probes are for people protection, not fish protection. They should always be used in conjunction with GFCI connected to everything electrical in your tank so the probe causes a trip for a leaky piece of equipment and not your hand when you stick it in the water. If you use a probe to drain off the voltage you will have a small current that can irritate fish and kill corals. Not sure why you get the reduced effect for each item unplugged, but I would bet you have a small leak in something (suspect heater first).
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you have something leaking volatge. I have had light fixtures that actually caused voltage issues in the tank, even when not touching the water. When you say it goes down, is it in even amounts based on devices or does it vary from device to device. Have you checked the outlets and made sure the polarity is correct and wired right. Is it a GFCI?
NeedBiggerTank
MTRC Member
Sorry to hear about your tang. 
pickupman66
5000 Club Member
which one did you lose? hate to hear that.. I have an actual grounding probe for an aquarium. AC will have one.
Unfortunately welcome to the club. I lost 15 fishes before I found 20v in my water.
AC has the titanium grounding probe for twenty something. After putting it in my water read 0.00v using a fluke meter.
I also had the same issue of not having a single offender. One power strip read 3v the other 8v etc and totaled 20v. I think it's because the wires are tucked into a metal wire management. Whenever I get my apex and pull out my sump to install it I'll redo the wiring.
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AC has the titanium grounding probe for twenty something. After putting it in my water read 0.00v using a fluke meter.
I also had the same issue of not having a single offender. One power strip read 3v the other 8v etc and totaled 20v. I think it's because the wires are tucked into a metal wire management. Whenever I get my apex and pull out my sump to install it I'll redo the wiring.
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You could have 120V in your water and the fish will not feel it. You put in a ground probe to drain it away and they will feel it when the current starts flowing. When you measure voltage to a grounded source, you see a difference. When fish swim through that 20V, they feel nothing -- because it is 0V differential to them and no current flow - like a bird sitting on a 25000V line. Only when you add the ground probe do they feel the current and can die. The proper application of a ground probe is to trip a GFCI when equipment insulation breaks down enough to allow 5 mA of current flow -- nothing more.
That being said, if something leaks it might be able to find a path to another leaky piece of equipment and cause dangerous current flow. On "high" energy pieces of equipment -- such as pumps or metal halide ballasts -- you might induce a field around that equipment that can cause an apparent voltage rise. High amounts of water moving can cause a static voltage rise. And this voltage would be harmless unless it found a path to ground and caused current flow.
Where do you measure your voltage? I would try from one side of the tank to the other and see if there is a differential. If not, your fish are fairly safe. If you measure from water to ground and get more than a few volts, you have insulation breakdown or a leak somewhere and need to find it.
Not saying some kind of insulation breakdown didn't kill your fish, but don't be so quick to rule 10V as the culprit if you can't isolate a single piece of equipment as the source.
That being said, if something leaks it might be able to find a path to another leaky piece of equipment and cause dangerous current flow. On "high" energy pieces of equipment -- such as pumps or metal halide ballasts -- you might induce a field around that equipment that can cause an apparent voltage rise. High amounts of water moving can cause a static voltage rise. And this voltage would be harmless unless it found a path to ground and caused current flow.
Where do you measure your voltage? I would try from one side of the tank to the other and see if there is a differential. If not, your fish are fairly safe. If you measure from water to ground and get more than a few volts, you have insulation breakdown or a leak somewhere and need to find it.
Not saying some kind of insulation breakdown didn't kill your fish, but don't be so quick to rule 10V as the culprit if you can't isolate a single piece of equipment as the source.
Dowtish
5000 Club Member
So Scott, are you saying that by adding a grounding probe that you find at the LFS, you are actually causing more harm than good? If there is voltage in the water, then I ground it out(making a path for it), that is what would cause harm to me or the fish?????
Break it down for us with little or no electrical experience.
orthokardia
Well-Known Member
+1
a bird can sit on a high voltage line all day with no ill effect, but if it ever touches two lines and the voltages flows then extra crispy.....just like the colonel likes it!
Using a ground probe is purely for people protection. It gives the current a path to ground that is not through your body. I say it is more harmful for the fish and corals because they are sensitive to really low current flows. I am okay with using ground probes provided you also use a GFCI receptacle for all electrical stuff in water (which should be done, anyway). That way any current over 5 mA that flows through the water would trip and let you know there is a problem. But I add this caution: one of the guys up in the Tri-cities area strongly suspects he lost his entire tank (corals and fish) because his GFCI (which tested just fine) did not trip when something broke and allowed the tank to be energized. In other words, he had less than 5 mA flow through the water to his ground probe for a couple days -- and came home to everything shedding flesh and dying.
All I have is a little bit of anecdotal evidence about coral sensitivity to low current. I am not an expert there. But I do know you could have 120V in a tank and so long as it is insulated from everything else it will not cause a problem (except, perhaps, copper leaching into the water from the electrical cable). Power transmission-level electricians work on high-voltage lines live by removing themselves from ground in a bucket truck and attaching themselves to the line they are working on (looks like a shark chain mail suit with a chain tail). They may be connected to 115kV, but they have 0V differential voltage between them and the line. In a tank, though, there can easily be a path to ground through a salt trace or a ground wire or the like that will make a single insulation failure on a motor or a crack in a heater a bit of a problem. But if you include a ground probe, you guarentee that path and that current flow.
All I have is a little bit of anecdotal evidence about coral sensitivity to low current. I am not an expert there. But I do know you could have 120V in a tank and so long as it is insulated from everything else it will not cause a problem (except, perhaps, copper leaching into the water from the electrical cable). Power transmission-level electricians work on high-voltage lines live by removing themselves from ground in a bucket truck and attaching themselves to the line they are working on (looks like a shark chain mail suit with a chain tail). They may be connected to 115kV, but they have 0V differential voltage between them and the line. In a tank, though, there can easily be a path to ground through a salt trace or a ground wire or the like that will make a single insulation failure on a motor or a crack in a heater a bit of a problem. But if you include a ground probe, you guarentee that path and that current flow.
Scott is correct. The ground probe essentially makes a path for the voltage to run down, in turn it actually goes thru the water column and thru the fish/coral, instead of just being in the tank with no ground. Now if you have a device like a pump that is leaking voltage and it has a ground prong on the plug, it could essentially do the same thing if the ground is touching the water thru a small crack/leak in the pump. I have a good example of this, the old RIO pumps were notorious for this. I actually had one crash my whole tank when it failed.
First place I always look for issues is pumps (if they have a cord in the water), then heaters. Its got to be one of those.
First place I always look for issues is pumps (if they have a cord in the water), then heaters. Its got to be one of those.
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