The other day i was doing a water change and i got a little zap. I had my hand in the water and bumped into my lights and i felt it. My first thought was that it was the lights so i got out the multimeter and checked it out and it turns out that its not the lights. When i bumped the lights with my arm and my hand was in the water it created a ground to the lights and thats what i felt. Right now there is about 15 to 20 volts of stray electricity in the tank. I have checked everything by unpluging one thing at a time. It seems that everything is contributing a small amount. When i unplug something the voltage would drop by 1 or 2 volts. So im not sure how to fix the problem. I also have a tang in the tank that has never acted right it is always twitching im sure that he is feeling it and now im starting to notice some pits in his face. I have read that it is thought that stray voltage my contribute to HLLE. All the other fish act okay. Will a grounding probe help? Is there anything i can do to stop the stray voltage?
Stray voltage and HLLE
- Thread starter BIG-G
- Start date
There are plenty of threads concerning the pro's and con's of using grounding probes ... from my perspective use of a grounding probe combined with a GFI plug is a must for the sake of the aquarist and every tank should have one .. I don't think it has any positive impact on the livestock. Most of those threads will be over at the newbie forum and not the disease forum.
Percula9,
That is horribly bad advice! A grounding probe will not eliminate the source of the shock this person received! "Stray voltage" or induced voltage of 15 to 20 volts is not in a range that can be felt by a human (unless possibly if you have a cut on your hand). In fact, it is unusual NOT to measure stray voltage in a marine aquarium that has powerhead, etc., in it.
BIG-G
If you receive a shock from your tank, there is a short. This can either remain stable, get better, or it can get worse. If it gets worse it can KILL YOU! It can get better if the short is due to the affect of humidity on salt creep, and either the humidity goes down or you clean off the salt residue. Sometimes you'll find an intermittant short that comes and goes, a damaged wire, leaking powerhead, etc.
Are all electrical items on the tank connected through a properly installed GFCI? If so, this should clamp down on the short if it ever gets bad enough to really hurt you. Otherwise, solve this problem before you work on the tank again - or work on the tank with the power off - or better yet, hire an electrician!
There actually was never any proof that stray voltage causes HLLE, certainly there was never any indication in my aquariums that grounding the tank had any affect on reversing the syndrome. We used to say that a much more likely cause of HLLE was the presence of di-hydrogen oxide (that's water for you non-nerds). The twitching has nothing to do wsith the HLLE or the stray voltage (remember, the fish isn't grounded, so there is NO current flowing through it).
Sorry to rant like that, but that was scary-bad advice.....
JHemdal
That is horribly bad advice! A grounding probe will not eliminate the source of the shock this person received! "Stray voltage" or induced voltage of 15 to 20 volts is not in a range that can be felt by a human (unless possibly if you have a cut on your hand). In fact, it is unusual NOT to measure stray voltage in a marine aquarium that has powerhead, etc., in it.
BIG-G
If you receive a shock from your tank, there is a short. This can either remain stable, get better, or it can get worse. If it gets worse it can KILL YOU! It can get better if the short is due to the affect of humidity on salt creep, and either the humidity goes down or you clean off the salt residue. Sometimes you'll find an intermittant short that comes and goes, a damaged wire, leaking powerhead, etc.
Are all electrical items on the tank connected through a properly installed GFCI? If so, this should clamp down on the short if it ever gets bad enough to really hurt you. Otherwise, solve this problem before you work on the tank again - or work on the tank with the power off - or better yet, hire an electrician!
There actually was never any proof that stray voltage causes HLLE, certainly there was never any indication in my aquariums that grounding the tank had any affect on reversing the syndrome. We used to say that a much more likely cause of HLLE was the presence of di-hydrogen oxide (that's water for you non-nerds). The twitching has nothing to do wsith the HLLE or the stray voltage (remember, the fish isn't grounded, so there is NO current flowing through it).
Sorry to rant like that, but that was scary-bad advice.....
JHemdal
jimwat
Premium Member
Another vote for the grounding probe.
All I know is that I had a fish showing symptoms of HLLE and my tank would give me a mild shock (I didn't really notice this until I had a small cut on my hand). I added a grounding probe. No more HLLE. No more shock. The probe has been in my tank for 3 - 4 years now.
Bad advice?? Maybe. But a little searching on the topic will show that this phenomenon is not unique to me.
Sorry jimwat, this is different, the person got a shock touching his light. Like I said in my post, you can feel stray voltage in the water if you are grounded and have a cut on your hand. A short to ground (in this case, the shroud of the light) is a different kettle of fish and needs to be resolved without a grounding probe.
In regards to your case of HLLE, that has been the problem all along - anecdotal cases where grounding probes worked, cases when they did not, but all were uncontrolled studies. Because of the chronic nature of HLLE, and the tendancy for people to fiddle with more than one variable at a time, (changing diet after adding a grounding probe, changing brands of carbon, etc) all you can say to reports like yours is "Great - glad it worked for you!"
Meanwhile, I attempted to run a controlled study with grounding probes and was never able to set up criteria that would induce and then resolve HLLE using them. I was able to do that with fish and carbon dust - HLLE would develop in the presence of minute amounts of dust and would go away when the dust was removed....
JHemdal
In regards to your case of HLLE, that has been the problem all along - anecdotal cases where grounding probes worked, cases when they did not, but all were uncontrolled studies. Because of the chronic nature of HLLE, and the tendancy for people to fiddle with more than one variable at a time, (changing diet after adding a grounding probe, changing brands of carbon, etc) all you can say to reports like yours is "Great - glad it worked for you!"
Meanwhile, I attempted to run a controlled study with grounding probes and was never able to set up criteria that would induce and then resolve HLLE using them. I was able to do that with fish and carbon dust - HLLE would develop in the presence of minute amounts of dust and would go away when the dust was removed....
JHemdal
jimwat
Premium Member
Actually, I do not think that this is any different. I was grounded to the floor (bare feet on tile), BIG-G was not grounded until his arm touched the light fixture. (Still voting to get the probe
)There is no "known" cause of HLLE. The electrical discharge theory is no better or worse than any other theory. And the problem with the carbon dust theory is that HLLE has presented in tanks that have never used carbon (link). My point is that sometimes anecdotal evidence is what it boils down to when trying to decided which reefkeeping technique is best for your tank (DSB, Vodka, Ozone,,,Grounding Probes. etc. etc.).
jimwat you are right in saying that i didnt get a shock untill i touched the light. What i think is happening is the stray voltage is present in the tank and the light is grounded when i touched the light it gave the current a place to go. It just happened to be through my arm. Its not enough to really hurt but i did no i had just been shocked. Im not sure what could be shorting out because as i stated every time i unplug something the voltage goes down a little. I have a grounding probe on order should be here friday. What i would like to know is will this remove the current?
jimwat,
The person who wrote that web page you linked to missed reading the section in "Advanced Marine Aquarium Techniques" that discusses HLLE and the link to carbon dust. I've posted it here before, but it is difficult to run searches on multiple search terms here, so I'll post it again:
Now remember, just because I wrote it myself does not make it any less valid, this has material been fully reviewed and edited. Unlike here on RC where anyone can write anything (which was what prompted me to reply to this thread in the first place), when you write a book or magazine article on a topic, there is somebody watching over your work to ensure accuracy.
Copyright 2006 TFH Publications
... Early on, carbon was implicated as a cause of HLLE but the mechanism proposed was that the carbon removed some compound that was needed by the fish, and its removal then precipitated the onset of the HLLE. In some of these recent public aquarium cases, the carbon in question was old, or used in a very small quantity so it was not conceivable that the carbon had substantially removed any compounds. The commonality here seems to be the production of carbon dust through mechanical abrasion inside the filter system. One theory is that the carbon dust enters the open lateral line pores, causing irritation and lesions. This would also explain why carbon-induced HLLE would not be commonly seen in typical reef aquaria; foam fractionators and filter feeding invertebrates are both well known for their ability to remove carbon fines from an aquarium’s water. It would also account for cases where some people use carbon in their aquariums with no apparent problem â€"œ there seems to be a huge variation between forms of carbon in terms of what types will instigate HLLE lesions and what types will not. Small-grained, dusty carbons seem to be the worst, while large granule or pellet forms seem to be less of a problem. It may turn out that further study will show that carbon derived from one carbon source over another may come into play.
In one case that demonstrates this syndrome very clearly, a pair of juvenile Australian lungfish were quarantined for over six weeks and then moved into an exhibit tank. They showed no signs of any problems. After a month or so, some driftwood decorations had caused yellowing of the water, so activated carbon was added to the power filter. The particles were small enough that they escaped the carbon container and were injected into the water. Within a few weeks, the lungfish developed unmistakable HLLE lesions. As the condition worsened, it was decided to remove the carbon from the filter and change all of the substrate (as it was contaminated with carbon dust). Within four weeks of removing the carbon, the HLLE lesions were seen to begin shrinking and within two months, the lesions were completely healed. Since these fish were actively growing, young fish and the lesions were noticed almost immediately, the problem was correctable. In aquariums where the fish are mature, the problem was not identified early enough, or where the carbon fines could not be 100% removed, it is unlikely that the aquarist will be able to resolve this problem.
While carbon dust in water may not be the sole cause of HLLE, it is most certainly one cause, one that the aquarist can take steps to avoid. At one public aquarium, once carbon use was curtailed, and all of the substrate was changed in problem aquariums, no new cases of HLLE have developed in the over 3000 fish in the collection for over three years.
The person who wrote that web page you linked to missed reading the section in "Advanced Marine Aquarium Techniques" that discusses HLLE and the link to carbon dust. I've posted it here before, but it is difficult to run searches on multiple search terms here, so I'll post it again:
Now remember, just because I wrote it myself does not make it any less valid, this has material been fully reviewed and edited. Unlike here on RC where anyone can write anything (which was what prompted me to reply to this thread in the first place), when you write a book or magazine article on a topic, there is somebody watching over your work to ensure accuracy.
Copyright 2006 TFH Publications
... Early on, carbon was implicated as a cause of HLLE but the mechanism proposed was that the carbon removed some compound that was needed by the fish, and its removal then precipitated the onset of the HLLE. In some of these recent public aquarium cases, the carbon in question was old, or used in a very small quantity so it was not conceivable that the carbon had substantially removed any compounds. The commonality here seems to be the production of carbon dust through mechanical abrasion inside the filter system. One theory is that the carbon dust enters the open lateral line pores, causing irritation and lesions. This would also explain why carbon-induced HLLE would not be commonly seen in typical reef aquaria; foam fractionators and filter feeding invertebrates are both well known for their ability to remove carbon fines from an aquarium’s water. It would also account for cases where some people use carbon in their aquariums with no apparent problem â€"œ there seems to be a huge variation between forms of carbon in terms of what types will instigate HLLE lesions and what types will not. Small-grained, dusty carbons seem to be the worst, while large granule or pellet forms seem to be less of a problem. It may turn out that further study will show that carbon derived from one carbon source over another may come into play.
In one case that demonstrates this syndrome very clearly, a pair of juvenile Australian lungfish were quarantined for over six weeks and then moved into an exhibit tank. They showed no signs of any problems. After a month or so, some driftwood decorations had caused yellowing of the water, so activated carbon was added to the power filter. The particles were small enough that they escaped the carbon container and were injected into the water. Within a few weeks, the lungfish developed unmistakable HLLE lesions. As the condition worsened, it was decided to remove the carbon from the filter and change all of the substrate (as it was contaminated with carbon dust). Within four weeks of removing the carbon, the HLLE lesions were seen to begin shrinking and within two months, the lesions were completely healed. Since these fish were actively growing, young fish and the lesions were noticed almost immediately, the problem was correctable. In aquariums where the fish are mature, the problem was not identified early enough, or where the carbon fines could not be 100% removed, it is unlikely that the aquarist will be able to resolve this problem.
While carbon dust in water may not be the sole cause of HLLE, it is most certainly one cause, one that the aquarist can take steps to avoid. At one public aquarium, once carbon use was curtailed, and all of the substrate was changed in problem aquariums, no new cases of HLLE have developed in the over 3000 fish in the collection for over three years.
BIG-G,
I'll urge you more more time not to confuse stray voltage produced by A/C motors and the like to a possible short in your tank. If adding a grounding probe to a tank would keep people safe, then every aquarium and bath tub would have one. They didn't come on the market until they were touted as a cure for HLLE. They never were intended to be a safety device!
Here is the section on electrical safety that I wrote in my Aquarium Fish Breeding book - the publisher wanted to take a very cautious approach to this topic - and this was the result: (at least read the last bullet point).
Electrical problems:
Water and electricity are a deadly combination. People have been killed working on aquariums when an electrical problem was present. Whenever possible, only choose aquarium equipment that has been approved by the Underwriters Laboratory, (UL listed).
• Never work on an aquarium in bare feet, or wet shoes.
• If you drop a pump, heater, or other electrical device into a tank, DO NOT REACH FOR IT, turn off the circuit breaker and unplug the item first.
• Never defeat the three pronged ground on any plug used around water. Always use a ground fault interrupt (GFI) system for all your aquarium’s electrical devices.
• Securely attach any electrical device (such as a light fixture) that is mounted over water.
• Should you see another person that has possibly been electrocuted, do not approach them to offer assistance until the electrical power to the area has been shut off.
• On humid days, dried salt on marine aquarium lids and their light fixtures can begin to conduct electricity. Prevent this by not allowing salt spray to build up.
• Signs of live electricity in a tank include bubbles in the water, gray cloudy water, and sometimes a burnt odor. The fish will most likely appear fine (Because they are not grounded, they do not receive a shock). Turn off the electricity to the area before servicing the tank.
• If you should get a slight shock from a tank, stop working, and resolve the problem at once. This sort of trouble may become more serious later on.
I'll urge you more more time not to confuse stray voltage produced by A/C motors and the like to a possible short in your tank. If adding a grounding probe to a tank would keep people safe, then every aquarium and bath tub would have one. They didn't come on the market until they were touted as a cure for HLLE. They never were intended to be a safety device!
Here is the section on electrical safety that I wrote in my Aquarium Fish Breeding book - the publisher wanted to take a very cautious approach to this topic - and this was the result: (at least read the last bullet point).
Electrical problems:
Water and electricity are a deadly combination. People have been killed working on aquariums when an electrical problem was present. Whenever possible, only choose aquarium equipment that has been approved by the Underwriters Laboratory, (UL listed).
• Never work on an aquarium in bare feet, or wet shoes.
• If you drop a pump, heater, or other electrical device into a tank, DO NOT REACH FOR IT, turn off the circuit breaker and unplug the item first.
• Never defeat the three pronged ground on any plug used around water. Always use a ground fault interrupt (GFI) system for all your aquarium’s electrical devices.
• Securely attach any electrical device (such as a light fixture) that is mounted over water.
• Should you see another person that has possibly been electrocuted, do not approach them to offer assistance until the electrical power to the area has been shut off.
• On humid days, dried salt on marine aquarium lids and their light fixtures can begin to conduct electricity. Prevent this by not allowing salt spray to build up.
• Signs of live electricity in a tank include bubbles in the water, gray cloudy water, and sometimes a burnt odor. The fish will most likely appear fine (Because they are not grounded, they do not receive a shock). Turn off the electricity to the area before servicing the tank.
• If you should get a slight shock from a tank, stop working, and resolve the problem at once. This sort of trouble may become more serious later on.
JHemdal, I understand i think what you are saying. If there is a short of some kind in the tank then the grounding probe may take the voltage out, but if i were to reach into the water and give the current another path (through me) I could still be shocked. As far as the HLLE I do run carbon although i dont replace it but about once a month.I did just replace it a week ago the tang has only been in the tank about a month and it seems that the enlarged pits on its face have only become clear within the last week. If the carbon may be causing HLLE , do you think that it could have came about this quickly after the carbon change?
BIG-G,
We've learned that it isn't the carbon itself that can cause HLLE, but the dust from some types of carbon. Protein skimmers are great at removing particulates (run some unwashed carbon on a tank and watch the skimmate turn black) so one hypothesis is that reef tanks often don't see HLLE for that reason.
I can't say if carbon has anything to do with your tang's HLLE, like I said, it is not the only cause. In my opinion though, it is highly underated as a potential cause. I only brought it up because jimwat stated there "is no known cause of HLLE." - which isn't true - I've proven carbon is one cause.
JHemdal
We've learned that it isn't the carbon itself that can cause HLLE, but the dust from some types of carbon. Protein skimmers are great at removing particulates (run some unwashed carbon on a tank and watch the skimmate turn black) so one hypothesis is that reef tanks often don't see HLLE for that reason.
I can't say if carbon has anything to do with your tang's HLLE, like I said, it is not the only cause. In my opinion though, it is highly underated as a potential cause. I only brought it up because jimwat stated there "is no known cause of HLLE." - which isn't true - I've proven carbon is one cause.
JHemdal
BIG-G,
I just got off the phone with my father (a retired electrical engineer). I explained the situation to him. He feels that the key was that you got the shock when you touched the light AND the water. He said that was due to the difference in electric potential between those two items - but not going from the tank to the light, but vice-versa. He said that grounding the tank will NOT reduce that potential, only reduce the potential between the water and ground. He says to be safe, you should look for a short in the light fixture, possibly caused by salt residue (he remembers 40 years ago when I lived at home and had 5 tanks in my 10'x10' bedroom - the walls got ruined by salt spray - grin).
JHemdal
I just got off the phone with my father (a retired electrical engineer). I explained the situation to him. He feels that the key was that you got the shock when you touched the light AND the water. He said that was due to the difference in electric potential between those two items - but not going from the tank to the light, but vice-versa. He said that grounding the tank will NOT reduce that potential, only reduce the potential between the water and ground. He says to be safe, you should look for a short in the light fixture, possibly caused by salt residue (he remembers 40 years ago when I lived at home and had 5 tanks in my 10'x10' bedroom - the walls got ruined by salt spray - grin).
JHemdal
Do you have this study available for viewing? You mention cases where carbon fines in the substrate needed to be removed to effect a cure - can you discuss these cases more in depth - for example what type of substrate was utilized? What were the substrate maintenance protocols?
mhltcob,
I'm not exactly sure what you are asking - I explained that I only *attempted* to run a controlled study on the grounding probe issue. For the carbon dust issue & substrates there is the case mentioned above with the Aussie lungfish. I have a half dozen or so other direct cause and effect cases that I've studied firsthand (so that I know other variables weren't changed). For the public aquarium example at the end of the excerpt - make that FIVE years and no new HLLE, except one minor case in a chevron tang in a coral exhibit with carbon on it. There was another public aquarium case involving a huge tank and a massive carbon dust release that caused acute HLLE, but I'm not at liberty to discuss their issue. The substrate type seems to be immaterial other than it is more difficult to remove carbon fines from some materials (thus the total substrate change done in some cases).
Carbon has been implicated for 30+ years in causing HLLE, but for all the wrong reasons - that it removes something from the water, that it contains a toxin that stresses the fish, etc. Remember when copper treatments were the latest "cause" of HLLE? What did many people do at the end of a copper treatment? Yep, add a ton of carbon to the tank!
I'm convinced that I've amassed enough data to prove this point, and I'm kind of tired being called to defend my assertion beyond what I've already published, while other people can simply parrot things like "a grounding probe is the only solution." with not receiving so much as one question about it.....
JHemdal
Please see the bibliography below, it chronicles my changing opinion on HLLE over the past 20 years.
*******************************
Hemdal, J.F. 2006. Advanced Marine Aquarium Techniques. 352pp. TFH publications, Neptune City, New Jersey
â€"â€" 2003. Head and lateral line erosion. Aquarium Fish 15(4):28-35
â€"â€" 1989. A reported case of head and lateral line erosion (HLLE), potentially caused by
a bacterial infection in a marine angelfish - Pomacanthus semicirculatus. Drum and
Croaker 22(3):2 3
â€"â€" 1989. Marine angelfish: color and style. Aquarium Fish 1(6):15 20.
I'm not exactly sure what you are asking - I explained that I only *attempted* to run a controlled study on the grounding probe issue. For the carbon dust issue & substrates there is the case mentioned above with the Aussie lungfish. I have a half dozen or so other direct cause and effect cases that I've studied firsthand (so that I know other variables weren't changed). For the public aquarium example at the end of the excerpt - make that FIVE years and no new HLLE, except one minor case in a chevron tang in a coral exhibit with carbon on it. There was another public aquarium case involving a huge tank and a massive carbon dust release that caused acute HLLE, but I'm not at liberty to discuss their issue. The substrate type seems to be immaterial other than it is more difficult to remove carbon fines from some materials (thus the total substrate change done in some cases).
Carbon has been implicated for 30+ years in causing HLLE, but for all the wrong reasons - that it removes something from the water, that it contains a toxin that stresses the fish, etc. Remember when copper treatments were the latest "cause" of HLLE? What did many people do at the end of a copper treatment? Yep, add a ton of carbon to the tank!
I'm convinced that I've amassed enough data to prove this point, and I'm kind of tired being called to defend my assertion beyond what I've already published, while other people can simply parrot things like "a grounding probe is the only solution." with not receiving so much as one question about it.....
JHemdal
Please see the bibliography below, it chronicles my changing opinion on HLLE over the past 20 years.
*******************************
Hemdal, J.F. 2006. Advanced Marine Aquarium Techniques. 352pp. TFH publications, Neptune City, New Jersey
â€"â€" 2003. Head and lateral line erosion. Aquarium Fish 15(4):28-35
â€"â€" 1989. A reported case of head and lateral line erosion (HLLE), potentially caused by
a bacterial infection in a marine angelfish - Pomacanthus semicirculatus. Drum and
Croaker 22(3):2 3
â€"â€" 1989. Marine angelfish: color and style. Aquarium Fish 1(6):15 20.
Jay,
If you were referring to me I didn't question the grounding probe because I have never thought it to be a factor. I agree with pretty much all of what your posts say.
I assumed that you ran a controlled study for carbon because of these quotes:
"I attempted to run a controlled study with grounding probes and was never able to set up criteria that would induce and then resolve HLLE using them. I was able to do that with fish and carbon dust - HLLE would develop in the presence of minute amounts of dust and would go away when the dust was removed"
"I've proven carbon is one cause"
It peaked my interest as I have not seen controlled studies done on this matter. Not to say that your findings aren't significant but they still represent anecdotal observations and are not quite the same as that of a data set achieved during a peer reviewed study. It would be interesting to apply your experiences to a more controlled/repeatable setting with measureable amounts of carbon dust being used.
mhltcob,
There are cases where "controlled studies" are not required to draw a conclusion to cause of a syndrome. Veterinarians do it all the time when they report findings from their case books. Since I am confident that I ruled out any confounding factors, I can draw conclusions without having to run standard controls. In two of these cases, the addition and subsequent removal of carbon dust was the only changing factor. In one case, I reintroduced carbon to the system, started HLLE again, withdrew the carbon and then it resolved again (this was as invasive as I wanted to get with the fish).
The crux of the problem for me is that I am not in a position to develop an invasive protocol to further test this idea. I would have to instigate the syndrome in fish and then euthanize them for study. This is akin to the study they did many years ago on pregnant women SCUBA divers. They started collecting data by asking questions of women who dived while pregnant and and found some horrific early data. I remember reading in Skindiver magazine - they pretty much said, "Stop diving if your pregnant, we don't want to collect any more data!" Same sort of thing for me - I've stopped using carbon so I don't have any cases to work on.
I will add that one person I spoke with has commented that the carbon connection may be a "public aquarium issue" since all but a few of my recorded cases have been with PAs. Although I don't think this is true, I cannot dismiss it out of hand. In the excerpt from my book, I discuss the idea that dusty carbons may be worse. I know that when I bought carbon, I purchased 50# bags based partially on price - while a home aquarist buying a premium jar of pelletized carbon would not be using the same product....it may end up being that only cheap bulk, unwashed carbon is the issue after all.
JHemdal
There are cases where "controlled studies" are not required to draw a conclusion to cause of a syndrome. Veterinarians do it all the time when they report findings from their case books. Since I am confident that I ruled out any confounding factors, I can draw conclusions without having to run standard controls. In two of these cases, the addition and subsequent removal of carbon dust was the only changing factor. In one case, I reintroduced carbon to the system, started HLLE again, withdrew the carbon and then it resolved again (this was as invasive as I wanted to get with the fish).
The crux of the problem for me is that I am not in a position to develop an invasive protocol to further test this idea. I would have to instigate the syndrome in fish and then euthanize them for study. This is akin to the study they did many years ago on pregnant women SCUBA divers. They started collecting data by asking questions of women who dived while pregnant and and found some horrific early data. I remember reading in Skindiver magazine - they pretty much said, "Stop diving if your pregnant, we don't want to collect any more data!" Same sort of thing for me - I've stopped using carbon so I don't have any cases to work on.
I will add that one person I spoke with has commented that the carbon connection may be a "public aquarium issue" since all but a few of my recorded cases have been with PAs. Although I don't think this is true, I cannot dismiss it out of hand. In the excerpt from my book, I discuss the idea that dusty carbons may be worse. I know that when I bought carbon, I purchased 50# bags based partially on price - while a home aquarist buying a premium jar of pelletized carbon would not be using the same product....it may end up being that only cheap bulk, unwashed carbon is the issue after all.
JHemdal
jimwat
Premium Member
I have not done a "controlled study", but my GUESS is that there is a latent charge held by the saltwater that is proportional to the number electrical cords hanging out of your tank (I have 9). I would also guess that if you removed each device from your tank, put them in a bucket individually and measured them for an electric charge, you would not find one (i.e. no short). Anyway, I would try the probe. Getting rid of the annoying little shock (IMO) is worth the $15 even if it does not solve the HLLE problem.
And a little thread fodder - Does adding carbon dust to saltwater increase its electrical capacitance?
[Discuss]
A grounding probe is fine to eliminate induced voltage, but it will not help you with leaking electrical equipment. For that matter total reliance on a GFCI isn't always a good idea either. The worse electrical shock I ever got from an aquarium system was with a commercial system that had a grounding probe and a GFCI. The probe did keep me from getting shocked on contact with the water, however, it didn't help me when I touched a pump that turned out to have a leaky power cord. Without a ground cord I would have gotten shocked when touching the water, and never gotten to the point of grabbing that pump. So the ground probe can actually hide faulty equipment till it's too late. Like Jay says, the fish aren't grounded, so it doesn't bother them.
Jay,
I will start with a disclaimer that I appreciate your insight and enjoy reading your work.
Veterinarians may be used as part of a puzzle to draw conclusions, but they can never accurately conclude anything without proper study format, or basing their conclusions off of others who have followed the scientific process. For example, a toxicologist might use veterinarian findings, along with path results, clinical observations, and blood tests to gain a set of data. This set of data is achieved using a study format which allowed for the manipulation of a single variable. From this data, conclusions can be drawn. All of this would undergo a review process to ensure its validity. Veterinarians might base there work down the line by citing this study or similar studies. However, a veterinarian can never draw accurate conclusions as to a cause with only a glimpse of the "effect" in hand (path reports, visual signs/observations). They need some more information, whether they establish it themselves or it has been prior established.
The process that you followed has not been laid out for adequate replication. Peers in the field have not reviewed your experimental design, results, and subsequent conclusions. To say that you have "proven" something with no data in hand is a bit of a stretch (not to mention that science works by ruling out alternative options rather than providing definitive proof). We don't even know the mechanism at play. Although I find your observations interesting and valuable, we must consider their differences from that of a controlled study. By repeating the procedure of adding and removing carbon along with controlling the variables as best you could, you have definitely added value to these experiences. Given adequate study design it is likely that one would achieve similar results in the lab. It is great to share these experiences and it seems quite reasonable to alter husbandry protocol in certain cases as you have done with favorable results. In the past, I have never thought of carbon as being a factor. It is hard to rule it out as most systems I have worked with have used carbon at one time or another. Personally I feel confident that nutrition is a factor. But again, this is all based on my anecdotal observations. With systems getting bigger and bigger and people employing carbon in more aggressive fashions, we might start seeing more cases of HLLE as a result. As you mention it would seem that velocity of flow though the carbon and brand of carbon would play a factor (hence why public aquariums may see this more often).
I will start with a disclaimer that I appreciate your insight and enjoy reading your work.
Veterinarians may be used as part of a puzzle to draw conclusions, but they can never accurately conclude anything without proper study format, or basing their conclusions off of others who have followed the scientific process. For example, a toxicologist might use veterinarian findings, along with path results, clinical observations, and blood tests to gain a set of data. This set of data is achieved using a study format which allowed for the manipulation of a single variable. From this data, conclusions can be drawn. All of this would undergo a review process to ensure its validity. Veterinarians might base there work down the line by citing this study or similar studies. However, a veterinarian can never draw accurate conclusions as to a cause with only a glimpse of the "effect" in hand (path reports, visual signs/observations). They need some more information, whether they establish it themselves or it has been prior established.
The process that you followed has not been laid out for adequate replication. Peers in the field have not reviewed your experimental design, results, and subsequent conclusions. To say that you have "proven" something with no data in hand is a bit of a stretch (not to mention that science works by ruling out alternative options rather than providing definitive proof). We don't even know the mechanism at play. Although I find your observations interesting and valuable, we must consider their differences from that of a controlled study. By repeating the procedure of adding and removing carbon along with controlling the variables as best you could, you have definitely added value to these experiences. Given adequate study design it is likely that one would achieve similar results in the lab. It is great to share these experiences and it seems quite reasonable to alter husbandry protocol in certain cases as you have done with favorable results. In the past, I have never thought of carbon as being a factor. It is hard to rule it out as most systems I have worked with have used carbon at one time or another. Personally I feel confident that nutrition is a factor. But again, this is all based on my anecdotal observations. With systems getting bigger and bigger and people employing carbon in more aggressive fashions, we might start seeing more cases of HLLE as a result. As you mention it would seem that velocity of flow though the carbon and brand of carbon would play a factor (hence why public aquariums may see this more often).
