fish disease?

"George Patterson" wrote in message news81If.23857$Eq.13398@trnddc02...
wrote:
If one of your pieces of equipment were leaking current into the water, the GFCI would trip.

You are correct, but it is important to know, it does not work like "all or nothing".

All GFCI are rated with a leak current detection threshold - they trip if the leak
current is bigger than a threshold and continue to work normally if the leaking
current is below the threshold. For many GFCI this threshold is set to the level
of 20-30mA. This is quite a strong current causing pain and musscle retraction
when applied to human skin. The purpose is not to kill a user only... but you
might still get zapped quite seriously and painful before the GFCI will trip.

And, what is more important in our aquarium applications: small currents
(below the threshold) continue to leak without being detected by GFCI...
So you can clearly have, lets say 5-10mA current leaking from your powerhead
failing insulation and your GFCI will do nothing to stop it. Will your fish feel it ?
We would need to ask them ;-)

It can be caused by injuries. I've seen it most often in
african cichlids.

Wayne Sallee
Wayne's Pets



wrote on 2/12/2006 10:20 PM:
Nerve damage? What could cause that?




On Sat, 11 Feb 2006 22:11:05 GMT, Wayne Sallee
wrote:


Could be nerve dammage. Nerve dammage will do that.

Wayne Sallee
Wayne's Pets



wrote on 2/10/2006 1:37 PM:


Hi,

I have a yellow tailed blue damsel that appears to have lost all of
the blue coloring (scales?) at the top of his head and around his
eyes. So he's mostly blue, but black in that area. He's been that
way for about 3 weeks, but he eats well and is very active, and
otherwise normal. All water parameters are normal. Anyone have any
idea what this is? I'm aware it's just a $4 damsel, but I've had him
almost ten years and I'm upgrading from a FO tank to a bigger reef
setup, and I'd like to see him make the switch. Any help would be
appreciated.

Thanks,

Grant

Also the nerve damage I have seen has involved the change
of skin color, rather than missing scales.

Wayne Sallee
Wayne's Pets



Wayne Sallee wrote on 2/13/2006 5:49 PM:
It can be caused by injuries. I've seen it most often in african cichlids.

Wayne Sallee
Wayne's Pets



wrote on 2/12/2006 10:20 PM:

Nerve damage? What could cause that?




On Sat, 11 Feb 2006 22:11:05 GMT, Wayne Sallee
wrote:


Could be nerve dammage. Nerve dammage will do that.

Wayne Sallee
Wayne's Pets



wrote on 2/10/2006 1:37 PM:


Hi,

I have a yellow tailed blue damsel that appears to have lost all of
the blue coloring (scales?) at the top of his head and around his
eyes. So he's mostly blue, but black in that area. He's been that
way for about 3 weeks, but he eats well and is very active, and
otherwise normal. All water parameters are normal. Anyone have any
idea what this is? I'm aware it's just a $4 damsel, but I've had him
almost ten years and I'm upgrading from a FO tank to a bigger reef
setup, and I'd like to see him make the switch. Any help would be
appreciated.

Thanks,

Grant

In answer to the previous questions, Mark, I installed the GFCI. I'm
not a qualified electrician--I know just enough to be dangerous.
They're easy to install, though. George, believe it or not, there's
no ground. No ground rod outside, no cold water ground, nothing. The
house was built in 1927 and I've owned it for 5 years. I've meant to
install one, just never have. Pszemol, in your opinion, a ground
probe can't hurt, even if it's somewhat redundant with the GFCI and
may actually be beneficial, correct? Wayne, it could be an injury.
He has a tomato clown pestering him constantly, but it's been that way
for years.

I guess that without a definite cause, I'll try to treat him through
process of elimination and see what works. Everyone, thanks for your
help, and any additional thoughts would be welcome.

Grant


On Mon, 13 Feb 2006 23:29:17 GMT, Wayne Sallee
wrote:

Also the nerve damage I have seen has involved the change
of skin color, rather than missing scales.

Wayne Sallee
Wayne's Pets



Wayne Sallee wrote on 2/13/2006 5:49 PM:
It can be caused by injuries. I've seen it most often in african cichlids.

Wayne Sallee
Wayne's Pets



wrote on 2/12/2006 10:20 PM:

Nerve damage? What could cause that?




On Sat, 11 Feb 2006 22:11:05 GMT, Wayne Sallee
wrote:


Could be nerve dammage. Nerve dammage will do that.

Wayne Sallee
Wayne's Pets



wrote on 2/10/2006 1:37 PM:


Hi,

I have a yellow tailed blue damsel that appears to have lost all of
the blue coloring (scales?) at the top of his head and around his
eyes. So he's mostly blue, but black in that area. He's been that
way for about 3 weeks, but he eats well and is very active, and
otherwise normal. All water parameters are normal. Anyone have any
idea what this is? I'm aware it's just a $4 damsel, but I've had him
almost ten years and I'm upgrading from a FO tank to a bigger reef
setup, and I'd like to see him make the switch. Any help would be
appreciated.

Thanks,

Grant

wrote:

.... a ground
probe can't hurt, even if it's somewhat redundant with the GFCI and
may actually be beneficial, correct?

The ground rod will help if you have a trickle leak into the tank (at least it
did on my tank). It may also have the additional benefit of causing the
defective piece of equipment to give up the ghost (again, it did in my tank).

It might be better to find out if you have a current leak, however. Buy or
borrow a decent volt/amp meter (Radio Shack is one source). Hook one lead to a
good ground and stick the other in the tank. Set it for alternating current and
see if it reads anything. I've not done this for my tank, but someone in this
group suggested it the last time this subject surfaced.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

Pszemol wrote:

Grounding probe, increasing leakage currents, will push
the small currents above triping threshold of the GFCI,
(only if GFCI installed).

If that's the case (and I'm not saying it isn't - your logic sounds good), then
the addition of a grounding probe would help determine which equipment (if any)
is faulty. Just unplug things until the GFCI doesn't trip.

I would be glad if some intelligent electrician explain this to me
and I could understand this way why people use g-probes for HLLD...

Well, I'm trained as an electrician (among other things) and do electrical work
(among other things). Quite a few people are of the opinion that I'm
intelligent. That doesn't mean that I understand why grounding the tank will
help with HLLD. All I know about it is that one of my fish developed HLLD
several years ago. A guy at an LFS told me a ground probe would cure it. I
installed one, and shortly thereafter, one of my powerheads bit the dust. The
fish slowly improved after that.

I believe that the ground probe did, as you suggest, increase the current flow,
causing the marginally faulty powerhead to fail. I further believe that the LFS
clerk was correct that the current leak into the water was causing the HLLD.

Like you, I don't see how a ground probe can help with HLLD as long as current
is free in the tank. I think it helps only by causing the current source to
fail, which stops the current flow.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

"George Patterson" wrote in message news:VteIf.21439$0H1.11817@trnddc04...
If that's the case (and I'm not saying it isn't - your logic sounds good), then
the addition of a grounding probe would help determine which equipment
(if any) is faulty. Just unplug things until the GFCI doesn't trip.

Correct.
But, a device might be faulty in such a way, that will leak the current
small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!
In this case, adding grounding probe will cause stray current which
would not exists if you consider high impedance of glass and stand.
(by "not exists" I mean in practical way, lets say it would be 100pA or 1nA)

That doesn't mean that I understand why grounding the tank will
help with HLLD. All I know about it is that one of my fish developed HLLD
several years ago. A guy at an LFS told me a ground probe would cure it. I
installed one, and shortly thereafter, one of my powerheads bit the dust. The
fish slowly improved after that.

Interesting, but still only an anegdotal evidence...

I believe that the ground probe did, as you suggest, increase the current flow,
causing the marginally faulty powerhead to fail. I further believe that the LFS
clerk was correct that the current leak into the water was causing the HLLD.

Like you, I don't see how a ground probe can help with HLLD as long as
current is free in the tank. I think it helps only by causing the current source
to fail, which stops the current flow.

I do not understand the expression "current is free in the tank"...
Must be some secret electricians lingo ;-)

My problem with understanding stray *voltages* (not currents) affecting
fish health is that voltage means NOTHING if you do not relate it
to some other potential, like ground. The way to "relate" a potential
of one point (water) to the second point (ground) is to use g-probe.

Try to understand my point he
when you measure voltage, and you read 120V, it means that
the potential BETWEEN TWO POINTS of the circuit is 120V.
It is assumed, for most cases, that the second point of reference
is ground, but it is not always a case - see birds sitting on a HV wire
example. They do not care how big potential is between the wire they
sit on and the ground BECAUSE THEY DO NOT TOUCH THE GROUND.
For that matter, you could measure potential of this wire to whatever
other conductor you like and get a reading from 0 to a milion volts
and birds would not care... Same should apply to fish in the glass
insulated tank... But somehow it does not. At least anegdotal
evidence shows that stray voltages matter for HLLD - but why ?

And this is a part of the story difficult to understand - help! Anybody ?

Pszemol wrote:

Correct. But, a device might be faulty in such a way, that will leak the
current
small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!

To clarify: You said earlier that a grounding probe "will actually INCREASE
the leakage currents flowing from the electrical devices!" If that is the case,
the flow would be more likely to trip the GFCI.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

"George Patterson" wrote in message news:P8nIf.25374$Eq.20667@trnddc02...
Correct. But, a device might be faulty in such a way, that will leak the
current
small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!

To clarify: You said earlier that a grounding probe "will actually INCREASE
the leakage currents flowing from the electrical devices!" If that is the case,
the flow would be more likely to trip the GFCI.

Let me explain again using examples as ilustrations this time:


Case 1: we have faulty powerhead - no grounding probe.
Insulator in the powerhead is leaking current to the water.
So the water column is under voltage to the ground/floor...
Due to the high impedance of glass and wooden stand
the current is limited to, lets say 2uA. GFCI does not trip
but the current flows and fish are affected...

After adding grounding probe, high impedance of glass
and wooden stand (acting as a current limiting insulator)
is bypassed and the whole leakage current is lead to ground
through the probe. The current increases and reaches
threshold which trips GFCI.


We replace the faulty powerhead with a good one and relax... :-)


Case 2: good powerhead with acceptable insulator, lets
say 100Mohms. This impedance 100Mohms will add to
equally high or higher impedance of glass and wooden
canopy and the stray, parasitic current flowing through the water
at 120V will be negligible. lets say 1/4 of a microamp (0.25uA).

After adding the grounding probe, high impedance of glass
and wooden stand is bypassed again, and the current is
limited ONLY by the powerhead insulator, this 100Mohms.
So adding grounding probe WILL INCREASE this stray
current to 120V/120Mohms = ~1uA. This current is too small
to trip the GFCI but the current flows and fish are affected.


Of course - every powerhead is different, they all will have
different insulator properties, they all will have different ways
to go bad etc... What I wrote above is just an example.
Note: adding a grounding probe to a good working tank might
increase stray currents to levels existing in a tank with faulty
electrical devices when no probe is installed... Go figure! :-)

You are correct Pszemol.

Grounding probes do not make things better for the fish.
The only thing that they do is protect the person, but
this is not why people install grounding probes.

The easyest thing to do is to get a vohm meter, and test
for leaking voltage, if votage is found, then unplug
everything, and then replug in stuff one at a time to find
out what is leaking.

Now the ideal system to do what people are wanting (but
too expensive) would be a computer that would moniter for
voltage, but in it's monitoring would only take in a small
amount of miliamps, then would present an alarm if such
voltage was found, and would selectively turn off all
items, and then turn on each item at a time to find out
wich item was leeking, and disable that item, and send an
alarm and declare wich item is bad. Naturaly this would be
a very expensive system. And you would have to decide what
amount of voltage leakage would warent shutting down the
item in your absents.

A simpler system would be something that would check for
voltage, taking in only a small amount of milivolts and
give an alarm when voltage is detected, allowing the
person to find the problem.

GFI systems only stop large amounts of electricity
leakage. Puting a ground probe will prevent you from
noticing small leakage of electricity when you put your
hands in the tank, or vohm meter in the tank.

Wayne Sallee
Wayne's Pets



Pszemol wrote on 2/14/2006 10:23 AM:
"George Patterson" wrote in message
news:VteIf.21439$0H1.11817@trnddc04...

If that's the case (and I'm not saying it isn't - your logic sounds
good), then the addition of a grounding probe would help determine
which equipment
(if any) is faulty. Just unplug things until the GFCI doesn't trip.


Correct. But, a device might be faulty in such a way, that will leak the
current
small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!
In this case, adding grounding probe will cause stray current which
would not exists if you consider high impedance of glass and stand.
(by "not exists" I mean in practical way, lets say it would be 100pA or
1nA)

That doesn't mean that I understand why grounding the tank will help
with HLLD. All I know about it is that one of my fish developed HLLD
several years ago. A guy at an LFS told me a ground probe would cure
it. I installed one, and shortly thereafter, one of my powerheads bit
the dust. The fish slowly improved after that.


Interesting, but still only an anegdotal evidence...

I believe that the ground probe did, as you suggest, increase the
current flow, causing the marginally faulty powerhead to fail. I
further believe that the LFS clerk was correct that the current leak
into the water was causing the HLLD.

Like you, I don't see how a ground probe can help with HLLD as long as
current is free in the tank. I think it helps only by causing the
current source
to fail, which stops the current flow.


I do not understand the expression "current is free in the tank"...
Must be some secret electricians lingo ;-)

My problem with understanding stray *voltages* (not currents) affecting
fish health is that voltage means NOTHING if you do not relate it
to some other potential, like ground. The way to "relate" a potential
of one point (water) to the second point (ground) is to use g-probe.

Try to understand my point he
when you measure voltage, and you read 120V, it means that
the potential BETWEEN TWO POINTS of the circuit is 120V.
It is assumed, for most cases, that the second point of reference
is ground, but it is not always a case - see birds sitting on a HV wire
example. They do not care how big potential is between the wire they
sit on and the ground BECAUSE THEY DO NOT TOUCH THE GROUND.
For that matter, you could measure potential of this wire to whatever
other conductor you like and get a reading from 0 to a milion volts
and birds would not care... Same should apply to fish in the glass
insulated tank... But somehow it does not. At least anegdotal
evidence shows that stray voltages matter for HLLD - but why ?

And this is a part of the story difficult to understand - help! Anybody ?