Fish Tanks

[mistymoo]

Can anyone help? I wondered if it was possible to "earth" the water in a fish tank. The metal frame is earth bonded but when a fault occurs in the equipment nothing trips as the water doesn't touch the metal frame.

I have ideas of what might work but I wondered if anyone else had come across anything like this before?

Ideas?

Reducing the voltage for the equipment is not really an option as all fish tank kit appears to be only available to work on 230 V.

Thanks!

 

[Barx]

Dont buy faulty gear...

Thought fish tank stuff all had transformers to step down and isolate supply. Bit dicey submursing 230V init. Especially if it made that poorly that it could cause live water. Should at least be class II double insulated surely.

 

[green-hornet]

All pumps, heaters and filters designed to be submersed in water are all class 2 equipment, with no connected earthing.

It would be unwise to have an earth rod inside the tank for the reason of equipotential differences effecting other circuits.

A fault effecting a socket circuit could easily transfer the voltage down the earth to the water and kill the fish or anyone who may have their hands in the wter at the same time.

 

[NozSpark]

Firstly all the equipment that is meant to go in a fish tank is made for the job and is submersible..

Secondly..... remove that bonding from the frame, you are increasing the risk to you and anyone else who might touch it

Thirdly..... lets just say that there was a fault and the water in the tank was "live"; there would be no current path through the fish so they would be OK --- it's just like birds sitting on overhead LV / HV cables.

If you want to increase the safety of your fish tank just make sure that it's fed through a RCD...... If it's a marine tank then do not use a RCD!!

 

[Apache]

If you want to increase the safety of your fish tank just make sure that it's fed through a RCD...... If it's a marine tank then do not use a RCD!!

why the difference for the marine tanks? Salinity?

 

[Andy™]

why the difference for the marine tanks? Salinity?

Fish tank

Marine tank

(or at least thats what i think Noz was on about!)

 

[Badger]

Fish tank

Marine tank

(or at least thats what i think Noz was on about!)

:^O :^O now that did make me laugh :coat :^O

 

[NozSpark]

Cheers guys PMSL.....

My thinking was that marine aquariums have quite a high value, once they are stocked, so you don't want your CU RCD to trip out and lose any of it.... so to speak..

 

[Apache]

Cheers guys PMSL.....My thinking was that marine aquariums have quite a high value, once they are stocked, so you don't want your CU RCD to trip out and lose any of it.... so to speak..

ah - thanks

 

[bob]

marine tanks are heated and have a high salt content i know coz u used to have one then got rid of it coz of to much matenece.

iws: go for tropical less matence and cheaper fish or if you are a lazy baz**d go for cold water no heater rqd the cheapest fish i have seen starts from...

wait for it

almost here

 

[mistymoo]

Ok. I'd better give you some more info. The tank is at my current place of work where I am not employed to do anything electrical.

The problem I have is that when the one of the electricians replaces the bulb in the UV clarifier he cracks the quartz tube. This mixes the water and the electrics. The fish are ok as they are not touching earth (as someone stated above) but when your's truely puts her hand in the tank she gets a shock. The RCD doesn't trip out as (and I may be wrong here, I've not been at the electrical game for very long...) as the electricity isn't leaking away anywhere it's just flowing through the nice conductive saltly water on it's way around the circuit.

The rest of the equipment is double insulated and designed to work under water etc, etc, I just need protecting from the cracking of the tube. I wasn't planning on removing the bonding from the metal frame, I was just considering the posibility of somehow extending the earth bonding into the water which would mean that when the sparky cracked the tube the next time the current had somewhere to go (other than up my arm) which would result in the RCD tripping.

I suppose the other thing I could do would be to get a more sensitive RCD which would increase the chance of nuisance tripping... which wouldn't be good as if it tripped at 5 pm when we all left for the day then it wouldn't be restarted until 8:30 am the next day. Most likely outcome- dead fish.

Thanks for your replies. And the pictures of the tanks. Reminds me of my most favourite joke ever...

Two goldfish in a tank, one says to the other, "How do we drive this thing!"

Ok so that's my sense of humour, now I've got that out of the way I promise I won't do it again.

M

 

[green-hornet]

It is not unusual to get a tingle from the water if live parts are present but the amperage is so low there is no rel danger.

I would try to educate the person who changes the light to be more carefull.

Most marine tanks have metal halide lamps,with no problems with electricity in the water, but with over a couple of grands worth of corals and fish I suspect they take more care.

 

[Andy™]

Cheers guys PMSL.....My thinking was that marine aquariums have quite a high value, once they are stocked, so you don't want your CU RCD to trip out and lose any of it.... so to speak..

so you would rather skip the RCD and fry the fish? not too bad if your selling stuff dead to the chippy...