What does Conductivity mean in Water?

Olympia

Well, the thread name is basically the question.
I have never heard anyone talking about conductivity in the aquarium until I started doing hardcore research into rainbowfish.
For example, a species conductivity range is:
Conductivity: 12−646 µS/cm (sorry it's in cm, Americans).

I'm just wondering, what does this mean? Is it relevant to anything? Should it be measured? That seems like quite a wide range, so I'm guessing not.

Tazman

Basically the waters ability to carry electrical current in relation to the amount of dissolved solids / ions.

Less ions = less ability to conduct electricity , more ions = more ability to carry electricity.

Here is a good article explaining it a bit more..

Olympia

That's interesting.
It's like hardness, and toxins in one? It seems like it'd be useful, yet not needed...
I don't even want to know how much the tester costs.

Tazman

Quick look at it seems $70-80 is about the price range.

Maxillius

hehe unless you have crocodiles or sharks that or eels that hunt with electric signals you wont need a tester like this :)

Olympia

Hmm, what about black ghost knives? They use electrical signals to navigate. :)
Posted via Mobile Device

Byron

Measuring conductivity is not something to worry about or fuss over, fortunately [provided we are doing water changes as noted below]. We have enough of that already in an aquarium.

As that linked Fluval article mentioned, conductivity just measures the TDS (total dissolved solids) in aquarium or habitat water. You will frequently come across "conductivity" rather than "hardness" in articles about natural habitats. Most of us think of hardness as GH and KH, caused by various minerals. And these are extremely important for fish. But so is the actual water in terms of the TDS which are related but not necessarily minerals.

As I mention in the article I recently posted on hardness, and again on salt, TDS get into the tank from all sorts of places. Fish food, water conditioner, medications, treatments, plant fertilizers, any chemical substance... etc. These too affect all fish. But fortunately we can control them easily by regular partial water changes. [obviously, this topic will form a major aspect of my forthcoming article on water changes.] We can't help adding TDS via conditioner and fish foods, but with regular water changes we remove them so they do not continue to build up.

You mention knifefish, and obviously such fish would be sensitive to TDS. But the water changes still deal with these adequately.

Byron.

Olympia

That was my thought too.. Another thing to measure?!
Good to know that is isn't that important to have numbers for.. Even the fluval article says that when conductivity increases it just means change the water.. which we do anyways.

Thanks everyone. :)