PDA

View Full Version : conductivity/tds



pops
03-10-2003, 10:48 AM
to all--IYO which would be better for ck hardness of h2o?
conductivity or tds. ??? ???
thanks :) :)

daninthesand
03-10-2003, 11:05 AM
In my opinion it does not really matter. You might want to borrow one though (if you can) so you can get familliar with it and with your water parameters. If you find your water is OK and don't have plans to make any changes to it, or breed discus, you may find that you will use the meter less and less and eventually it will collect dust. JMO.

Remember too that these meters measure salt related solutes as well, so don't forget to include a Gh/Kh test kit as well. If your water has a salt content and measures a high TDS or conductivity it might be due to salt. The test kit will not measure the salt and give you a truer reading of your water's hardness.

HTH

Daniel

brewmaster15
03-10-2003, 11:26 AM
For general hardness... probably TDS meter. It measures the number of part per million of Minerals in solution.

Conductivity meters measure the degree those parts of minerals actually conduct current.

Technically I Think they both use a similar method to acquire that data..its all in how its interpreted.

I could be wrong though ....

OH Randal... This ones right up your alley!

hth,
al

RandalB
03-10-2003, 01:56 PM
Pops,
Simply put, some people like Conductivity readings some like TDS it's actually a matter of personal preference. Both are a way of determining the quantity of dissolved minerals in water.

Any TDS test meter you buy will be reading conductivity and converting it to TDS by dividing the result by 2. A true TDS tester costs hundreds of dollars. So the best you will be getting is an aproximation.

This thread has some additional information:

http://forum.simplydiscus.com//index.php?board=1;action=display;threadid=287

Daniel is also exactly right, you need a test kit to determine Carbonate hardness as TDS/Conductivity meters only register General Hardness.

HTH,
RandalB

Carol_Roberts
03-10-2003, 07:46 PM
This link shows how to use a TDS meter ;D
http://forum.simplydiscus.com//index.php?board=21;action=display;threadid=7845;st art=0#lastPost

gary1218
03-10-2003, 08:45 PM
Go with the conductivity meter.

GARY

fcdiscus
03-10-2003, 09:22 PM
I agree with Gary! It is a more universal standard! Frank

dm
03-10-2003, 10:26 PM
Randall don't you mean you would multiply the result by .5 or alternatively dividing it by 2? You have me confused.

RandalB
03-10-2003, 10:45 PM
OOPS!
I mean the TDS meter measures conductivity and divides by 2 to get the PPM TDS reading.

I've posted this so many times today I got confused.

TDS meter= Conductivity meter with a circuit to convert to TDS

THEY ARE BOTH MEASURING THE SAME THING

RandalB


The best way to go is to get a meter that measures both ;)
I've got 'em if anyone is interested. (they measure temp with 0.01 +- accuracy too!)

pops
03-11-2003, 01:16 PM
so RandleB, what do they go for?
thanks :)

RandalB
03-11-2003, 01:40 PM
Pops.
$60.00 including shipping.

Here's a link to more info about them:

http://www.hannainst.com/products/testers/dist5-6.htm

It is the DiST 5

RandalB