Aquarium chemical reactions ? Voltage measered...

[NSWPHIL]

Hi All,

I just wanted to see if any others know a bit about the chemical reactions that go on in our aquariums.

Obviously in hard water, we have many minerals which include metals and salts.

This is in part, how a battery works.

If you have a low PH, then you've essentially a low acidic solution with metals which creates a voltage.

I tend to feel low voltages on my hands if I have a sensitive bit of skin, such as cutting my nails too short so they're tender underneath, so I can feel 'electricity' in my aquarium (I know exactly what It feels like, it's not the PH scale). I decided to see if my multimeter picked up anything from the aquarium water, I got a rating of 0.05 volts DC with all my filters and pumps etc. So I disconnected everything from the aquarium, unplugged all cables from sockets and removed fittings from the aquarium so no capacitors had any residual voltage being delivered to the water. Crazily enough, the reading on the multimeter went up to 0.20 volts DC, which to me would indicate I likely have a short on one of my devices, otherwise there should be no change (unless it's because the water in my sump has an effect on it.

When I got my first aquarium off my father when I moved out, I got an old internal aquarium filter, which had a very strong electrical voltage in the water, so I threw it in the bin. It may have been running in the tank for quite some time before I noticed, but the fish didn't seem phased. (now I have completely new gear, literally everything is different)

My question after my BS story, is what effect does this have on my fish ?

I will try to get the PH to 7.0 and see if that makes any difference. My tank is 450 litres, so dropping the PH from 8.3(tap water) can be quite a task. I change the water every few days (maybe 20%), trying to get my congo's to grow fast. I was going to use rain water until I realised it was a PH of 9.7 when it fell, and only dropped to about 8.8 after a week.

If only the chemical and mineral mixture in the aquarium was always the same, you could probably make a ph meter based on the voltage output.

[__CAV__]

I don't believe it has any effect as the water acts like a faraday cage.

Raising your ph won't do anything either, only real way is to use pure water as its the impurities in your water which allow current to flow thru it.

Only real way to stop it is to use water that has no impurities in it ie. ro/rodi/rainwater etc.

[NSWPHIL]

But rain water is not pure, perhaps 20 years ago it was. But this day in age contains too many contaminates, hence why the PH is not 7. It's really alkaline here, and i live in rural NSW.

I know it takes about .2 -.6 amps to kill a human, but requires a voltage high enough to break through the skin and tissue's resistance in order to travel trough the body and get to the heart (if it doesn't go through the heart then it won't necessarily kill), over about 0.6 amps causes the heart to go into a tense like state with intense pain, but you may live through it due to the heart going into that state.

I think you're right about the water acting as a Faraday cage, providing you DO have enough minerals in the water to allow the current to flow in the water with little resistance around the fish as opposed to through it. If the voltage were high enough, it would likely effect the fish also, but in this circumstance, the voltage needs to break through the resistance of the fish's skin/scale tissue, but wouldn't be high enough. My tesla coil with 25kV will allow me to experiment (not on live fish).

Thanks for you reply, i think you hit the nail on the head with the Faraday cage scenario.

[Lictoga]

I had a power head short in a 4ft tank while I was cleaning it I got hit with quite a lot of voltage, blew my arm out of the tank and felt like I was hit with a sledge hammer, but all my fish were fine and didn't feel it, probs because the tank was on wooden stand and insulated the I earthed it. Also rain water might be easy to drop the ph depending on how much buffer is in your town water.

[thatsright99]

Rainwater with a ph of 9.7??? And tapwater of 8.3??? Really? Where do you live? Under the chimney of some industrial .plant or mines? Are you sure the measuring method is correct?.

When I collect rain I let it rain, and I mean rain not just drizzle or showers, for half an hour b4 I think about collection. Have you tried that to see if there's a difference? I've also noticed a change from when caught and left for a week, but rain here in bris starts at 6.6-6.8 and goes to 7.

At least you have straight up good water for tangs.

[efc]

Interesting.... Pollution normally creates acid rain. Are your rainwater tanks concrete by any chance? Or concrete tiled roof?

[Oromis]

One solution to "stray currents/voltage" in a tank is earthing (using an earthing probe) which is supposed to solve induced currents, from magnetic fields (light ballasts, electrical wiring, etc)

I have never used one.. Or am I certain they do as they say. But its an idea to look at

Adjusting pH will not really affect the voltage measured. It will sometimes but adjusting to 7 will not get rid of any voltages

Ultimately there will always be chemical electric potential in a tank (redox) and there is nothing that can be done about that.. (Plus that occurs in nature due to salts in the water)

My guess on the last one is that as long as water conditions match what a fish naturally lives in it shouldn't have any effect? If not a good effect

Edit: After a quick look around. Ground probes can cause big problems if something fails (e.g. a heater breaks) short circuiting to ground and though the water/fish between the device and the probe..

Also voltages are just the difference in potential between two points. Thus usually a voltage between two different non connected things means very little. Just like measuring your speed in relation to mars, it kinds gives you a big meaningless number.

A voltage from one side of the tank to another on the other hand would be a issue, but not so much to ground.

Edited September 28, 2013 by Oromis

[Mitch86]

It may have been said already but the electricity will have no effect on the fish unless they are earthed to the ground, In that case they have bigger problems then lol

[__CAV__]

I had a power head short in a 4ft tank while I was cleaning it I got hit with quite a lot of voltage, blew my arm out of the tank and felt like I was hit with a sledge hammer, but all my fish were fine and didn't feel it, probs because the tank was on wooden stand and insulated the I earthed it. Also rain water might be easy to drop the ph depending on how much buffer is in your town water.

The reason you got a boot (electrocuted) is that u where at a different potential voltage, ie. the tank was at 230v while you were at 0v. electricity like water flows from areas of high pressure to low pressure (voltage is the electrical equivalent of pressure, where as current is your flow) and will always take the path of least resistance.

The faraday cage theory is right too, google how they maintain overhead hv lines, there's a vid on YouTube explaining it more, i'll have a look and see if I can find it for you

Edit- found it google high voltage cable inspection and its the first vid on YouTube, it goes for 3.10

Edited September 28, 2013 by __CAV__

[NSWPHIL]

I live in Dubbo NSW, about 4.5 hours west of Sydney. I don't actually have a rainwater tank, it all gets wasted..

However, i disconnected the gutter pipe and allowed the water to collect in a 60 Litre tub, which i would then empty into a 250 Litre tub so i had a little 'soft water' to use in my aquarium. It had been raining for hours before i done this, the roof on the garage is painted iron. It's been a while since it last rained though, so it may be that there is ALOT of dirt/dust in the gutters on the garage, also on the roof. I done some research and found people were getting different readings every time it rained in whatever locations they lived in, sometimes 5.5, sometimes 9 etc. I would imagine i should get some of these variances when i collect the rain, and if i had a water tank, the overall PH of combined rain collection would be much lower, likely 6-7. The Macquarie River is about 7.2

I have a 1000 Litre tank in my shed and a 450 Litre tank in the house, therefore i would need a decent size water tank to accommodate for water changes. I do keep my aquarium PH at 8.3 according to my electronic PH Meter that i don't calibrate. Strangely enough the angel fish have spawned/layed eggs a number of times in these conditions over the past 18 months and the congo tetra won't leave the females alone, the eggs that aren't eaten usually end up with fungus though because it's a heavily planted tank with alot of lighting.

[Donny@ageofaquariums]

my electronic PH Meter that i don't calibrate

did you use this to test the rainwater?

if so I'd double check it with a cheap basic liquid test.