How Do Tds Meters Work?

[craigybaby37]

brought myself a tds meter from ebay and ime just qurious as to how they work. i know you give it a sample of whatever water u want testing and it gives you a reading.

But whats is it a reading of exactly??? is ive read they test for nitrates ammonia copper etc etc....so do you scroll through a list of results once its done testing???

 

[smithrc]

brought myself a tds meter from ebay and ime just qurious as to how they work. i know you give it a sample of whatever water u want testing and it gives you a reading.

But whats is it a reading of exactly??? is ive read they test for nitrates ammonia copper etc etc....so do you scroll through a list of results once its done testing???

It works by testing the conductance of the water between the 2 electronic probes.
the conductance rises the higher the dissolved solids

they don't test for specific minerals etc - the TDS stands for total dissolved solids so it measures everything and gives you one reading.

 

[craigybaby37]

ah rite i see thanks for that.

so when ime testing the water from my RO filter it should in theory read 0 as it quotes to remove 99% of contaminants??

 

[k.o.d]

No because there is still the 1% that will cause impedance, I work on the fact that if it brings myTDS down from 400 to 4 or 5, then it is still doing its job and is working at the right percentage

 

[smithrc]

No because there is still the 1% that will cause impedance, I work on the fact that if it brings myTDS down from 400 to 4 or 5, then it is still doing its job and is working at the right percentage

^^ what he said

 

[pengy666]

Hmm 4 or 5 is high in my opinion but good still, My RO man filter says once the reading gets to about 5 ppm it needs the filter media changing! I have been using existing filter for around 4 months now and its creeped up to 1ppm from 0ppm!

just my opinion!

 

[SkiFletch]

Hmm 4 or 5 is high in my opinion but good still, My RO man filter says once the reading gets to about 5 ppm it needs the filter media changing! I have been using existing filter for around 4 months now and its creeped up to 1ppm from 0ppm!

just my opinion!

Depends on your input Pengy. Someone with 500ppm in will get ~5ppm out. Someone with 100ppm in will get ~1ppm out.

 

[australia]

what tds should my african cichlids live in?

 

[SkiFletch]

Usually at least 100TDS is good for them, more is fine, less is not so fine. They're used to hard water.

 

[australia]

Usually at least 100TDS is good for them, more is fine, less is not so fine. They're used to hard water.

thanks alot for your reply

i heard that 800TDS to 1100TDS should be used?

 

[SkiFletch]

Sure, why not? I'm no cichlid expert, just know they come from really hard water.