Conductivity, and TDS meters

[DJTSA WI]

I am using 100% R.O water with Kents R.O added back in. Currently I'm added one tsp per 5 gallons and have no way to confirm the hardness that I'm at. I need to buy a meter but get confused between Conductivity and TDS. Which one would I need and whats the difference. I also need to know which one tests for KH. Which meters are good and wich one to stay clear of.
Please help. ???

[Carol_Roberts]

They both kind of measure the same thing. Here is a thread on how to use one http://forum.simplydiscus.com//index.php?board=21;action=display;threadid=7845
RandalB, who is a moderator here, has some really good deals on them. He has a special through 4/16/03 for a Hanna meter for $30. Here is the link http://forum.simplydiscus.com//index.php?board=13;action=display;threadid=8291

[Ardan]

Hi,
the only way to test for KH is to test with a reagent type kit. the meters don't measure it.
The reagents (drops or tablets or dip strips) will measure the amount of carbonates in the water, also called alkalinity. this affects only the ph and ph stability.
the hardness meters, or other reagent tests , measure GH or tds, or conductivity (ms). all depend on amounts of calcium and magnesium (mainly).

hth

[DJTSA WI]

Thanks thats what I needed to know. My fish should be happier for it.

[gary1218]

I agree with Carol. Whatever you decide to buy I would buy it from Randal. It's hard to be his prices AND service.

Also, I would recommend a conductivity meter over a tds meter. I think he sells a Hanna meter that is a combination conductivity meter and pH meter. That would be my choice.

You can check out the Hanna Instruments at www.hannainst.com


GARY