Is there a way of measuring CO2 electronically?

Tom Barr

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Yes, mostly via pH/KH or a KH reference cell, then the pH/KH chart.

Or watch close and slow and progressively adjust.
 

Anka

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Thanks Tom - do you know a way of digitally monitoring or recording water hardness in the form of kH or gH? Or any other form of hardness that can be recorded and then converted to gH and/or kH?
 

Tom Barr

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Anka;83472 said:
I ask because I am buying a photometer to determine the colours using light spectrum analysis - but it doesn't test hardness.

Several companies make hardness photometers.
Be good to have on hand.

Hanna makes a multi meter that does that and alkalinity, NO3, PO4, K+, Fe etc.

Not sure you need all that, just KH and GH, and pH meter.
 

Anka

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The one I'm getting is a multiparameter photometer, measuring:
- pH
- Nitrate
- Nitrite
- Iron
- Copper
- Chlorine
- Ammonia
- Phosphate
- Dissolved Oxygen

but no hardness >.
 

Anka

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Hi Tom,

I'm getting this: http://www.hannainst.com.au/learn_more/i:HI+83203

It's a bit expensive ($750 for unit and $700 for reagents) but it does everything.

No need for pH as I have a probe that measures that.

Can alkalinity be converted to kH?

Is total hardness equal to general hardness? (or can be converted)

That alkalinity photometer says it is for marine aquariums - so I will call Hanna and asked them if it is appropriate for FW. Or do you know for a fact it will be fine for FW?

Cheers
 

Tom Barr

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Alkalinity is KH as far as we are concerned, in marine systems and few others, borate contributes to the alkalinity, but for FW, it's all KH.
Poly Phosphates can influence KH in FW also, these are sometimes used to lower pH but they do not add any CO2 obviously.

The Hanna unit you are looking at is a bit pricy. So are the reagents.
I'd just get a decent NO3 test kit, KH, and pH.

I hardly ever test anything anymore.

Most is done by plants, algae, fish appearances/behavior.

Light I'll test more than anything these days.
Then CO2 very carefully.

Nutrients, not at all.