Question: Substitution for conductivity meter

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Ag8n asked on February 12, 2018 00:48
235 | 2 answers | shortlink

Is there a reason why an aquarium type TDS ( Total Dissolved Solids ) meter couldn't be substituted for a conductivity meter?

Granted, they are no where near as accurate as a conductivity meter. But...They are dirt cheap and they do indicate dissolved solids.

Any help would be appreciated. Thank you.

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gretchengehrke 3 months ago

Hi @Ag8n, Do you know how the aquarium TDS meter works? Maybe it really is just a super cheap conductivity meter?

Ag8n 3 months ago

I think it is. Was hoping someone was more familiar than me. Different websites talk about charge and others about conductivity, which can be two different things. Tell you what. I know a wastewater plant manager and lab equipment salesman. Let me touch base and see what I find out.

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2 Answers

Check out:


All tds meters are conductivity meters, but according to the article, they may not all use the same conversion factor. There have to be some that still display conductivity.

Ag8n 3 months ago

Sorry. Truncated the internet address: Https://

Ag8n 3 months ago

I checked Amazon. There are several tds meters that also do conductivity for a price of under $20.
Since a scientific model lists for about $1000, you wonder what differences there are between the instruments.

warren 3 months ago

wow!!! This is very cool. Here's an amazon link:

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I love this idea. Here are some leads on connecting a TDS meter to an Arduino, if that's what you're interested in: (using this $32 sensor)


This one for $24 looks optical, for sure, so not conductivity-based:


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