# Electrical Conductivity



## Cichlid soul (Mar 6, 2011)

I have a 120 gallon aftrican (rift lakes) cichlid tank, with a fluval G6 filter. The filter has an electrical conductivity sensor. I would like to know what is a safe range to set the "alert" to. Originally, I had it set between 400 and 600, but now that the 6 week old estasblished tank is testing some nitrAtes (at 10ppm), the conductivity has gone up to 611. Everything else is testing fine (Ammonia 0; Nitrites 0; KH 9; GH 13).

What is the BEST EC range for this tank?


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## Swerved (Mar 9, 2011)

I'm assuming it's measuring in Ã‚ÂµS/cm ..

I can't tell you what a "safe" range is for your fish, but I can tell you that it seems logical to me that as the water gets impurities over time (nitrates, waste, minerals from rocks, etc) the conductivity will creep up. It should go back down when you do your routine water changes, so what I would do is see how high it goes before your routine water change. Do this a couple of times over the course of a few changes so you can get some sense of where the EC will routinely be when the tank is in need of maintenance, then set the alarm slightly above that level. That way the normal operating parameters of the tank won't trigger the alarm, unless you get behind on maintenance or something has gone wrong.


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## fmueller (Jan 11, 2004)

It is true that in a lab environment conductivity can be used as a measure for the purity of water, because very pure water has a low conductivity that rises when any compound is dissolved in the water. In a fish tank this is virtually useless, since the conductivity rises with *any* compound that is dissolved in the water, including salts that are beneficial for fish like rift lake cichlids. In other words, by measuring conductivity you cannot distinguish between harmful and beneficial compounds. In a rift lake tank the conductivity due to salt is going to be sky high, and the slight change caused be added fish waste is going to be negligible in comparison.

The only example I can think of where measuring conductivity to monitor water purity would be useful for the aquarist is with fish that demand ultra clean and very soft water - discus breeding setups come to mind. For a rift lake setup it would be best do disable this gadget.

As a side note, I am fairly disappointed to hear about a reputable company like Fluval incorporating an electrical conductivity sensor into an aquarium filter, since the only reason I can think of is to create marketing hype :roll:


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## Swerved (Mar 9, 2011)

Yes, electrical properties are often used. It is sometimes stated in terms of conductivity and sometimes in terms of electrical resistance. You will commonly see these specifications on the different grades of deionized water where it's used, along with other specs like total dissolved solids.

I read the G6 manual just to see why they say it's good to monitor. To me it seems that feature is not really useful for someone who keeps up with their aquarium routinely. The reason I say that is because if you're used to testing your aquarium with test kits, they already tell you what you need to know. It could be used like I said also, kind of as a very general reminder to let you know you need to check your tank, but really it's not of much more use than that. It seems you can turn the alarm off, as well. It's a nice system for one who likes data and gadgets.

There are just too many different factors that can affect conductivity to consider it a diagnostic means in my humble opinion. pH, ammonia, nitrates, nitrites, hardness, and alkalinity will tell you more than enough about how your tank is doing. No need to bring sand to the beach.

Not knocking the G6 at all, it looks like a nice system; I'm using Fluval as well.


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## prov356 (Sep 20, 2006)

> As a side note, I am fairly disappointed to hear about a reputable company like Fluval incorporating an electrical conductivity sensor into an aquarium filter, since the only reason I can think of is to create marketing hype


Agreed, useless gadget for 99.999% of fishkeepers out there. I'd ignore or disable it. It's probably not even accurate. Keep it simple.


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## Cichlid soul (Mar 6, 2011)

Thank you to all the responded, the information was very helpful. I am testing my water weekly and doing water changes every 2 weeks, so I do know what's going on. I like to idea of determining what my tanks "typical" EC range is, and set the alert there, but as was said, it will only indicate a "change", not useful information on it's own.

I was only concerned because I have read that the EC for Lake Malawi is much lower that of Lake Tanganika, and I have fish from both lakes in my tank, and very few, if any, are "wild caught" anyway.


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## prov356 (Sep 20, 2006)

> I was only concerned because I have read that the EC for Lake Malawi is much lower that of Lake Tanganika, and I have fish from both lakes in my tank, and very few, if any, are "wild caught" anyway.


I've kept 'WC' and tank raised tanganyikans, bred them, and never worried a whole lot about much except keeping buffers up, so pH doesn't crash. I think you'll find the majority of keepers out there have experienced the same. At least from what I've read here at CF. Manufacturer's of filters would do well not to give aquarists some other thing to worry about that they don't need to worry about it. But if they can get us to be concerned about it, the filters with these devices will be flying off the shelves. I believe that's the big goal.


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## PfunMo (Jul 30, 2009)

Seems we spend far more time inventing market hype than actual product improvement. Bah!


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