Backyard Aquaponics
A place to discuss aquaponics

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OK - red faced, I write that I slaughtered my fish.. every one of them

35 Silvers... 6 Salmon... 16 Trout... RIP..

Water vitals were perfect.. They were all pretty happy.. There was still SOME salt in the system from start up, but I still don't have the capacity to measure it (soon to be addressed)

I added the 16 advanced trout fingerlings, and as with best practice I salted, to help with assimilation and any possible diseases.. That is all perfectly normal.. BUT..

There was an existing problem, and correction steps for which were being taken..

I would occasionally get a small tingle when I put my hand in the (PIST) sump.. The PUMP was leaking power.. most likely because it was uncovered on a couple of occasion, b4 I installed a run-dry protection..

This fault had remained for a few weeks with no ill-effect to man or fish.. whilst I investigated pumps and finally ordered replacements..

The problem seems to be that likely, when I salted to 3.5ppt, the conductivity of the water rose and electric currents flowed through the system.. ( Accurate measurement - Post Mortum - 3.620PPT )

I had incorrectly felt that a fish floating in the water, would not be affected by small currents within the water body.. Clearly that is wrong.. Very WRONG..
( Consider Voltage gradients... V/CM )

I had deliberately neglected having an RCD on the AP system, because of issues of possible nuisance tripping, that MIGHT happen, when away from the site.. (something I would never tolerate with Children around)
I felt that there was more chance of system catastrophe, from everything turning off, than the chance of electrical injury, that I am pretty aware of, and encounter often in my normal work..

It is interesting that a good friend lost MANY of his loved fish, when his pump blew, and at that time, I convinced myself that it was more the chemistry of failure, rather than electric currents, that would have been the cause..

What I would like, in hindsight, is a device that will activate an alarm, during earth leakage detection..
This, I feel would give ME the chance to fix a minor problem, whilst giving the fish, the chance of normal habitat, whilst the problem is fixed..
Perhaps an ideal would be a device that "Alarmed" at say 10mA and trip at say 30mA..

( and Knock-Knock - the new pumps just arrived at the front door..)
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Are you sure? I have never heard of anyone electrocuting their fish, normally if there is a short it blows a house fuse and the fish are fine.. I've seen this happen or heard of it happening a few times, but never hurt any fish..

Also tingling in the water can be related to grounding earth faults in your house wiring, same thing as whhen people get a tingle through the bath taps or shower taps. I've know people that have had this problem many times in the past, going to the fish tank with bare feet in the wet you get a tingle of earthing, with boots o and in the dry, nothing... In this case, as it's an earthing ( ie the tingling) issue a RCD won't help anyway because they trip on difference between phases or to neutral rather than to earth... I believe.....

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RCD - Residual Current Detection = measure exact current in L and N and if difference, then it MUST be going somewhere ELSE = anywhere including to earth..

EB - you may have now guessed that my surge in interest in Fish Diseases, was sparked from my catastrophe.. I believe that I had crossed off other possibilities..
I may NEVER be 100% certain, but seriously debilitated Mountain Cloud fish, removed from the water, recovered in time..

NO - I am not certain, but our friend Gordon, is reasonably confident of the possibility..

PS - having removed 2/3 of the water and replacing it with rain water, has resulted in no observable electrical conductivity.. but the PUMP will be replaced tomorrow (and the old one inspected)
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Nup... I didn't put two and two together that way, but the tingle thing? I have asked multiple electricians about it and an electrical engineer, one of my best mates is an electrician who owned an electrical engineering company for decades, they all told me the same thing, not a fault of the device as such, but a wiring issue within the house to do with earthing..

And it's come up here many times over the years... Bunson, had a pump of ours that he swore must be a problem because of the tingles, back at the shop we got no tingles of any sort in many different situations. He didn't get the problem from a different brand pump.. Now From memory, One of them had an earth cable within the pump cable and the other didn't..

I would bet that if you take the pump to another persons house and try it there, you'll find no tingles.. Not that I am really suggesting such a thing just in case...

Here's something I found on one of the ABC sites...



Anyway, the upshot of all the research and asking I have done on this subject in the past was always "get a competent electrician to look at your house wiring, it can be dangerous..." Another also said, find your earth stake, usually below your meter board, pour a bucket or two of soapy water over it, letting it drain into the ground well, see if the tingle goes away..

I think NOT having RCD protection on your system is not a good idea! I'll say it stronger - I think it is verging on negligence. Your life (or that of other people) is more important than your fishes!

I concur with EB - most tingles are due to differences in potential between 'Earth' and the Neutral. The further the system is away from the house the worse this can be as 'earth' may not be all at the same potential either depending on whats going on in the local system.

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BTW - the house has the usual RCD's... I was talking about a separate one at the system.. which is where i will eventually have a protection system..

and it's interesting that having replaced the pump - no more tingles.. Just a coincidence perhaps..

BUT.. a big BUT... What happens when a two wire (Double Insulated) device goes leaky..
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and I just retrieved the old pump from the sump (had trouble dismantling and getting it out the narrow gap..)

I shoved it in a small tub.. added water.. Added salt.. Capped the outflow to stop a serious mess..

Turned it on with a MultiMeter connected between a stainless knife and earth and got 13Vac..

So the question is one of fish anatomy - what sought of voltage gradient can they exist within, without screwing up their nervous system..

We know that 240V will stun them seriously.. Anyone come across any study on ac voltage tolerances..?
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Thats strange... I wonder if it will do it at a different house/shop with a different electrical wiring system...

BuiDoi, you might find this paper on electrofishing of interest. http://nptel.ac.in/courses/120108002/mo ... ture10.pdf This method is used for fish surveys and if done properly the fish fully recover. It may shed some light on voltages and currents that affect fish. This is not my area of expertise, but I doubt your pump that produced 'tingles' would be sufficient to kill your fish without killing you too

I hope the new pump works out and you have fish again soon.

when I was a kid my uncle and I (mainly him) would kill trout with small stick of dynimite... this was back waters of NZ and kind of hill billy community.

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OK - I AM IN REAL TROUBLE now....
New pump.. no electrical leakage
New AIR pump.. much more air to stones..

All water figures ZERO and pH of 6.2

All seemed ready to try more fish, but to be cautious just ten went in at midday..
They smashed food at 2pm and were belly up at 5pm..
Removed to a hospital tank and looking seriously ill..

There just must be something in the water, 2/3 of which was changed after the last disaster..

SO - Plants Tomatoes, Apple Cucumber, Basil , carrots, and sweet potato..
and that DuckWeed pool..

Possible issues - we have some old BBQ burners in ponds - rusting away

There is tiny amount of bright green algae in open water amongst the duckweed.

Any thoughts as to where to start??

Peter
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That's terrible news Peter
Has anyone nearby sprayed for termites or spiders, or crop dusted nearby? It could be a toxin that has drifted in. Clutching at straws really, but it does sound like a toxin. Are you sure your WQ kit reagents are okay - can you get hold of another kit to check? Does your hospital tank have an alternate source of water or the same as your AP system?

Hope you find the cause and a solution.

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It is pity-full to watch them dying one by one..

they were moved to a special tank with filtered water plus some salt. and lots of air
Whatever slam-dunked them, is serious in it's speed, and that is all after replacing 2/3 of the water with rain water..
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Could the electricity have converted something in the system to something toxic?

Different media could have different reactions to electricity.