MJ pump gone bad and shocked me
- Thread starter TitansFan
- Start date
rcmike
Active member
Well, it's not exactly the same thing. Kinda like this video. http://www.youtube.com/watch?v=Z3q9WdjD5wc
DMBillies
Active member
Scientists (and perhaps rednecks) routinely electrofish. Scientist, for the most part, then release the fish which presumably mostly survive... I daresay rednecks are more likely to put them on the wall than to release them. I don't know the specs on that equipment and what a fish can typically withstand without long-term effects, but I have to imagine that someone does.
mamagoose45
Member
Since electrofishing was brought up and I can chime in here with a little bit of knowledge/experience as to the fish impact, I figured I would. Granted all of my experience has been with FW stream/lake fish, I imagine it is all still relevant to SW fish. I took a few fisheries classes in college and busted out my notes/books to snag the official terms, impacts, etc.
Fish respond in two ways to electroshock...behavior/reactive movements or trauma from stress. Most electrofishing is done using continuous DC current to reduce the impact on fish. But in the case of the tank, it would have been AC current which is much harsher on fish.
The behavior/reactive moments can be shown two ways with AC current - oscilltaxis (forced movement w/out direction - this would look like thrashing because of the alternating current) and tetany (imobilization) depending on the intensity of the current and proximity to the source.
The trauma from stress shows up as hemorrhages in soft tissue (looks like branding marks on the fish), secondary infections from lesions, and bone fractures (compression of vertebraes as a result of thrashing).
As far as how trauma varies across species, there a few factors that come into play. Bony fishes conduct more readily than cartilagineous fishes, as do fishes with fine scales. The larger a fish is, the greater it will be affected as total body voltage increases with length. Other factors that impact the intensity of the shock are temperature, substrate, and water conductivity.
A blurb out of my "Fisheries Techniques" book for class:
"...Unlike water conductivity, fish conductivity cannot be directly measured, but it can be estimated (Kolz and Reynolds 1989). When water is less conductive than are fish (ie. low water conductivity), current tends to flow through the fish, making voltage gradient more indicative of electrical effects than current density. However, when water is more conductive than are fish (ie. high water conductivity), current tends to flow through water, around the fish, making current density more indicative of electircal effects than voltage gradient..."
There is a chart in the book that clears this mumbo jumbo up a little bit, but I figured it's good to know. If anyone really feels the need to delve into this further, I can bring the book to the next meeting.
Just my two cents...
Fish respond in two ways to electroshock...behavior/reactive movements or trauma from stress. Most electrofishing is done using continuous DC current to reduce the impact on fish. But in the case of the tank, it would have been AC current which is much harsher on fish.
The behavior/reactive moments can be shown two ways with AC current - oscilltaxis (forced movement w/out direction - this would look like thrashing because of the alternating current) and tetany (imobilization) depending on the intensity of the current and proximity to the source.
The trauma from stress shows up as hemorrhages in soft tissue (looks like branding marks on the fish), secondary infections from lesions, and bone fractures (compression of vertebraes as a result of thrashing).
As far as how trauma varies across species, there a few factors that come into play. Bony fishes conduct more readily than cartilagineous fishes, as do fishes with fine scales. The larger a fish is, the greater it will be affected as total body voltage increases with length. Other factors that impact the intensity of the shock are temperature, substrate, and water conductivity.
A blurb out of my "Fisheries Techniques" book for class:
"...Unlike water conductivity, fish conductivity cannot be directly measured, but it can be estimated (Kolz and Reynolds 1989). When water is less conductive than are fish (ie. low water conductivity), current tends to flow through the fish, making voltage gradient more indicative of electrical effects than current density. However, when water is more conductive than are fish (ie. high water conductivity), current tends to flow through water, around the fish, making current density more indicative of electircal effects than voltage gradient..."
There is a chart in the book that clears this mumbo jumbo up a little bit, but I figured it's good to know. If anyone really feels the need to delve into this further, I can bring the book to the next meeting.
Just my two cents...
rcmike
Active member
In the SW tank I get 1.5K ohms at about 6" apart. With the freshwater I can't get a reading. This is using my cheapo multimeter. Not sure if that is right though. I looked it up and Wikipedia says the conductivity of seawater is 5 seimens per meter and drinking water is .0005 to .05.
Pickupman66
New member
some interesting voltage readings I got. I have a fairly nice Calterm digital multimeter. like mike measured, scored about 7.5kohms in resistance in the water at approx 6 inches distance between probes. on measuring voltage in tank to see if you have stray voltage leaking into the tank, placed + probe in water and neg probe to known good ground. got reading of 0.1 volt. ergo, I have some voltage available in the tank. meter did fluctuate around .01-.03 milliamps. also when I open the hood and place 1 electrode in the water and leave one out under the lights, I get a voltage reading of .1volts. I also got a reading just by placing the probes under the hood, when removed, got no reading.. I have heard that VHO lights can give off voltage, and after playing with the meter, I can see this.
cannot get the probes on a fish to get a reading. they are a little shy unless I have food or they think I have food.
cannot get the probes on a fish to get a reading. they are a little shy unless I have food or they think I have food.
gflat65
New member
I got the crap shocked out me yesterday while hooking up a MH cord to the ballast. It is PFO, so it has sockets and receptacles. I was reaching behind the ballast to plug the socket in with the cord in my left hand and my right hand feeling around for the MH socket. As soon as I touched it I felt alive again
.
.
Mdwannabe
New member
Want to feel alive, try what happened all the time when I worked at a Electronic Air Cleaner factory.
We had hundreds of collection Cells sitting on skids, and they made great seats, when trouble shooting units.
Some folks found it funny to put the cells in a test unit and charge them to almost 40,000 DC volts (next to no amps), and remove them from the test rack without discharging them, and put them back on the storage skid. That made them nothing more than a very high voltage, quick discharge battery.
You guessed it, Murphy dictates every cell you grabbed to use for a seat was charged, and their was never any doubt about who just sat on a "Hot Seat", the sound could be heard in every corner of the factory!
I think that is where my creative use of single syllable words comes from
At least the Ionizer's had no capacitance ability, they ran at over 100,000 volts, and it only took one accidental shock from these to teach you a lesson! AHH, The smell of Ozone and burning flesh in the morning, you know you're going to have a good day.
We had hundreds of collection Cells sitting on skids, and they made great seats, when trouble shooting units.
Some folks found it funny to put the cells in a test unit and charge them to almost 40,000 DC volts (next to no amps), and remove them from the test rack without discharging them, and put them back on the storage skid. That made them nothing more than a very high voltage, quick discharge battery.
You guessed it, Murphy dictates every cell you grabbed to use for a seat was charged, and their was never any doubt about who just sat on a "Hot Seat", the sound could be heard in every corner of the factory!
I think that is where my creative use of single syllable words comes from
At least the Ionizer's had no capacitance ability, they ran at over 100,000 volts, and it only took one accidental shock from these to teach you a lesson! AHH, The smell of Ozone and burning flesh in the morning, you know you're going to have a good day.
