what are you using for a probe
That special stainless steel welding rod. I think it's called 316.
what are you using for a probe
I would get your earth leakage checked.
Marcel do you know if you have an earth leakage switch in your house?
Someone may have changed it for a normal overcurrent breaker.
Yes I do. I'm renting the place, so I'm not sure how good it works. It tripped many times already for various reasons. That's why I think it's working. Maybe not to the exact 20mA.
@lIghty What were you trying to say here?
I just double checked the broken pump. It has got a 3 prong plug. So why didn't it trip the earth leakage?
I would get your earth leakage checked.
Marcel do you know if you have an earth leakage switch in your house?
Someone may have changed it for a normal overcurrent breaker.
YES, Marcel is correct in saying its causes electrolysis, however is the example in earlier posts a true reflection of what happens in your tank? I don't believe so. NO offense Marcel!
What happened in the experiment is obviously not what happened in my system. Otherwise everything would have been dead without no time!
So I agree!
The reason I say this is as follows:
For there to be electrolysis there has to be current flow, now if you have enough current flow to cause electrolysis there's a problem, and electrolysis is the least of of your problems IMO! By removing the earthing / grounding probe you could compare it to leaving some wires exposed without insulating them, I don't know about you but I don't like playing Russian roulette? Is it safe?
And again, what is the percentage of grounded tanks?
Electrolysis is a serious problem for me, because I lost almost all my livestock. Things hasn't changed with just 20 Volts stray voltage until I disconnected my ground probe. And I don't see it as russian roulette as I can check the stray voltage at any time before I work in the water and could connect the ground probe via switch when working in the water.
One could test the current flow by putting their DVM (digital multimeter) on to mA and check the flow by placing the meter between the probe and earth terminal (same way as described to test voltage), anything more than 20mA should be tripping the Earth Leakage switch (for E.L. switches rate at 20mA).
Thanks for that. Will do so.
To try limit the little "current flow" from your fish if you are concerned about it, would be to place a probe or probes as close to the pumps as possible, this should reduce the flow "across" the tank, however I cannot confirm this 100%, but from my knowledge I'm sure it would work.
Bottom line, if you have stray voltage, find the source and bin it!
A brand new sicce pump brings 6 V into the water and each heater 7 V.
Many appliances come with some stray voltage, maybe just caused by electric field. Definitely, I never ever will install a pump internal!
I find your opinion to this topic a bit disappointing as you are the expert in electricity. There might be maybe some problem with the earth leakage here in the house, but who can be sure that everything is working according to the law?
What are you going to suggest to reefers, which have maybe 50 Volt stray voltage?
That amount adds very quick. A return pump, heater, skimmer pump, etc.
Buy everything new? Used equipment should be then certified as stray voltage free!
We don't really know what is going on in case of stray voltage. To many things are playing together, which we can not determine.
I had a cube running with 70 Volts stray voltage. I grounded the tank and that was it. Nothing negative visible. No dropping PH, corals and fish were fine. Here I have only 20 Volts and when grounded the PH drops by 0.1. The fish stops eating, turns shy, swims strange, turns blind and finally dies.
I think we all should put our heads together and find a solution that is safe for us and the inhabitants.
Can somebody make a poll about how many stray voltage others have and if they grounded the tank or not?

I'm not sure why you say your disappointed with my reply? I gave you my opinion that it is safer to have an earth rod, than removing it as one is worried about secondary "problems" it could causes since the "primary" problem has been neglected.
Because I gave lots of food for thought. I brought up a solution. Not saying it's the perfect solution, but something to start working on.
And your "badge" made me disappointed!maybe I should use more smileys in my post. I like to provoke a bit to get things going.
As stated by NJ and myself, get the E.L. tested, Marcel its not worth taking any chances.
I am not a chance taker. And I want to learn more about electricity. I'm quite good with it, but when it comes to electronics, not so much.
I would and have said to anyone having a problem is to isolate to device causing the problem and replace it, there is nothing else one can do to repair it! unless you want to play with your life, I sure know I don't.
Stray voltage is not related to how many pumps you have, its related to how many faulty pumps you have!
Agreed, there are many factors involved, and we can get extremely technical on this topic, however, it won't discredit the fact that a tank is safer with a ground probe.
I under stand your frustration WRT the other tank having problems with grounding, however there must be something wrong with one of the pumps or something.
The pump is brand new!
Try unplug ALL the attached devices, place the DVM between the probe and earth set to mA, and plug one item in at a time, you should soon find the item/s causing the problem.
Will do so and post it here.
Just because the pump runs it doesn't mean it safe, so yes, buying used equipment has its risks. If I find a pump or device with a problem, I cut the cord right where it enters the pump, this way no one can use it again.
That is very nice of you, but I highly doubt that the majority would do that as they would not know about a problem regarding leakage.
As for trying to find a solution to this problem, I'm busy brain storming a couple ideas, but I will take a bit of time, and test accurately could be a bit tricky
Now I have you there, where I want you to.I will help you!
I'm really not here to fight or argue, I just don't want to loose another MASA family member.
I guess you refer to Herkie. I could not imagine that something like that could happen.![]()
Is there a way that every reefer can test that their earth leakage switch in their mainboard really works and their wall socket used for the tank is 100 % in working order when it comes to to more than 20 mA?
There are ways but are unsafe for the average joe, the best would be to buy a E.L. tester, R368 from ACDC
20 mA is nothing and extremely safe IMO! So having that, I shouldn't have lost anything as it should have tripped long ago before producing bleach and acid!
Or am I wrong here?
Chill, sit back, open aand have a look at your wonderful aquarium. Thanks for the insightful thread guys.
Cheers!

I wouldn't say that 20mA is nothing, as its enough to cause damage. and yes, I wouldv'e expected the E.L. to trip long before you had such bad problems, hence I'm concerned about your E.L. switch and wiring.