Electric issues result in chemical issues?

[bcardoro]

Hi all!

This thread is gonna be about "an experiment" could say, it was not my purpose of course, but I hope the outcome may help other reefers that suspect of electric issues. First of all, I am writing this thread from Spain, so sorry if any expression is not correct or something is written wrong.

Let me contextualize the situation. My system is a 140 gallons tank, and has been running for about 1year and 4 months. The purpose was to aquaculture some corals in my collection, so I set up the tank as a frag tank (14'' tall), with 44 pounds of live rock. I cycled the tank for 2.5 months, and started adding corals. 1 month after have added the SPS corals, they started to die (seriatopora first, then montis). I have had SPS thriving and dying before, so I know how they die. This time was more like they were burned. After SPS, it was the turn of LPS corals. To save them, I moved them to two friend's tanks and they recovered well, so clearly something was not ok in my tank.

Since then, the system has been more like a rollercoaster than a saltwater tank. I checked everything I could: parameters (did ICP's, nothing rare), no rust on the equipment, PAR lighting, flow pumps... and found nothing suspicious, but a reading in my voltmeter, plus I was feeling electricity (sometimes the shock was considerable) when I touched the water tank. I read that stray voltage was not an issue so I slowly took my corals back to my system, and after 1-2 months they started to look bad again. I have been in this mood for 1 year and I am really tired, so here I am, hoping that someone has something to say.

Here it comes the thing. When I found the stray voltage, I could not find the culprit. And the problem was that I was taking as the ground, my ground's floor itself which is made of rubber (is that kind of floor used in gym's to avoid damage when a weight falls on the ground) instead of the outlet ground. Eventually, I noticed that when I was measuring tank voltage with respect to the outlet ground, the result was 0, but when measuring with respect to the ground, the reading was between 3 and 22V. Apparently, that ground material where the system is placed accumulates charge and at some point, this charge passes through the aquarium to the grounded outlet using the tank equipment. So the first question is: can this be an issue? May it stress corals or perturb the water chemistry?

Today I have seen the same kind of burned on a few corals (yesterday they were fine), so, in view of my experiences, I first checked my outlet ground and something was not ok, then I went to the ground's floor and found 58V (measuring ground floor - ground outlet). In the floor, near the tank stand there is usually salt, so I suspect that, maybe, an electric current is generated from the floor to the house's ground through the tank equipment, and it burns the corals.

I have not been able to find any experience like this on the forum. Does it makes any sense?

Many thanks in advance.

B

 

[Brew12]

I am so sorry you are having these issues! I think I understand what you are trying to get across.

Stray voltages may or may not be a problem. We have two main voltage sources in our tank. The one that doesn't cause issues is an induced voltage. This is from magnetic fields that are in or near our tanks. The one that is a problem is a fault voltage. This is where electricity has found a path outside of its intended insulation barriers.

My first questions is, do you run your system on an RCD?

We can rule out a static charge being built up on the mat and going through the aquarium. Static charges can reach very high voltages but have very little current. They would dissipate with very little energy transfer.

ICP's are a wonderful tool, but they can only tell us a limited amount of information. An ICP only tells us levels of elements, it can't tell us what compounds these elements are in. For this reason it cannot detect toxins. For submerged electrical faults we can look for elevated copper levels but not much else.

Have you taken a voltage from exposed metal on your light fixtures to the outlet ground? It is possible an external source of electricity is energizing you while you are insulated on the rubber flooring. When you touch the water, it has a path to ground which is why you feel the shock when you put your hand in the tank.

 

[Randy Holmes-Farley]

If you have current flowing from a live wire to a ground, there are all kinds of bad chemistries that happen at the wire and ground, such as copper release and chlorine formation.

But induced voltages (e.g., a high voltage source near the seawater induces a voltage in it without actually touching it) such as you are experiencing do not, I do not think, result in these same sort of chemical issues, at least not to an important extent.

 

[bcardoro]

I am so sorry you are having these issues! I think I understand what you are trying to get across.

Stray voltages may or may not be a problem. We have two main voltage sources in our tank. The one that doesn't cause issues is an induced voltage. This is from magnetic fields that are in or near our tanks. The one that is a problem is a fault voltage. This is where electricity has found a path outside of its intended insulation barriers.

My first questions is, do you run your system on an RCD?

We can rule out a static charge being built up on the mat and going through the aquarium. Static charges can reach very high voltages but have very little current. They would dissipate with very little energy transfer.

ICP's are a wonderful tool, but they can only tell us a limited amount of information. An ICP only tells us levels of elements, it can't tell us what compounds these elements are in. For this reason it cannot detect toxins. For submerged electrical faults we can look for elevated copper levels but not much else.

Have you taken a voltage from exposed metal on your light fixtures to the outlet ground? It is possible an external source of electricity is energizing you while you are insulated on the rubber flooring. When you touch the water, it has a path to ground which is why you feel the shock when you put your hand in the tank.

Many thanks for your reply Brew12.

The outlets are all connected to the same net of our living floor, and it does have an RCD. Does it makes any difference? The weird thing today is that I took my voltmeter to check the ground: it should give 0V in one case and 240V if we exchange the voltmeter probes right? Well, on the whole living floor it is ok, but in the room where I have the tank system it gives 60V and 110V respectively, which is very weird (this did not happen before). I do not know if it is related with my tank equipment, but it is likely since there is nothing else connected in that room.

I just took the voltage from my hydras and hybrid T5 fixtures to the ground, and it gives 0V. Only when I measure with respect to the mat it gives non-zero voltage, either mat-tank or mat-ground outlet, gives similar value.

I forgot to mention that when the mat is dry, there is no shock, but when it is wet and I step on it, then I feel the electricity. This is why I thought the problem was static electricity accumulated by the mat.

If you have current flowing from a live wire to a ground, there are all kinds of bad chemistries that happen at the wire and ground, such as copper release and chlorine formation.

But induced voltages (e.g., a high voltage source near the seawater induces a voltage in it without actually touching it) such as you are experiencing do not, I do not think, result in these same sort of chemical issues, at least not to an important extent.

Thanks for your reply Randy. ICPs have never revealed copper, always 0ppm, so I guess there is no wire exposure.

 

[Brew12]

The outlets are all connected to the same net of our living floor, and it does have an RCD. Does it makes any difference? The weird thing today is that I took my voltmeter to check the ground: it should give 0V in one case and 240V if we exchange the voltmeter probes right? Well, on the whole living floor it is ok, but in the room where I have the tank system it gives 60V and 110V respectively, which is very weird (this did not happen before). I do not know if it is related with my tank equipment, but it is likely since there is nothing else connected in that room.

Are all the outlets in the room protected by the RCD or just the outlet for the aquarium? The reason I ask about the RCD is that if you get a shock from a fault voltage by anything protected by an RCD, the RCD should trip. If you don't trip the RCD then it can be a static or induced voltage issue.

It is very curious with the voltage on the flooring. I am not sure what to make of that yet.

 

[bcardoro]

Are all the outlets in the room protected by the RCD or just the outlet for the aquarium? The reason I ask about the RCD is that if you get a shock from a fault voltage by anything protected by an RCD, the RCD should trip. If you don't trip the RCD then it can be a static or induced voltage issue.

It is very curious with the voltage on the flooring. I am not sure what to make of that yet.

Everything is protected by the RCD (theoretically), but it is true, it should trip and it does not. Maybe it is not sensitive enough...?

Anyway, thanks for your time guys. I am not sure whether I will be to figure out what is going on, still we will move to another house in 4 months, hope not to have these issues in the new one