re: Alkalinity-CO2-Test Kits

To: Aquatic plants list <aquatic-plants at actwin_com>
Subject: re: Alkalinity-CO2-Test Kits
From: Cynthia Powers <cyn at metronet_com>
Date: Wed, 15 Jan 1997 17:26:16 -0600 (CST)
---------- Forwarded message ----------
Subject: Re: Alkalinity-CO2-Test Kits
To: Aquatic-Plants at ActWin_com
Date: Wed, 15 Jan 1997 10:16:28 -0500 (EST)

> From: Daniel Marsh <dmarsh at premier1_net>
> Subject: re: Alkalinity-CO2-Test Kits
> 
> According to the bottle "Electro-Right adds the right balance 

	Right balance for what?

> of
> electrolytes and trace elements including potassium, magnesium,
> chloride, sodium, calcium, sulfate, iron, vanadium, titanium, strontium,
> and manganese" no percentages or quantities. I was under the impression
> that you had to start with something like this to be able to measure
> anything. Please feel free to correct my misinformation and advise a
> better product or way to start from DI water.

	The plants should be able to use some of this stuff, but why one
would want vanadium, strontium or titanium added to a freshwater
aquarium is beyond me.  I use RO water, because my well water is very
hard, but I just add about 20% of the well water to the RO water.
If you want to avoid using tap water at all, but want _some_ hardness,
I would suggest adding a _measured_ amount of powdered CaCO3, which
will dissolve slowly.  CaCO3 + H2O + CO2 -> Ca++  +  2HCO3-
This will give you a known amount of hardness, carbonate hardness, and
alkalinity, which should provide an interesting check on your test kits.

> We were hoping for an _accurate_ CO2 test, 
>
	Why are you worrying about the exact amount?  Measuring CO2
accurately in a sample of water is tricky at best; if you are at all
slow about it you will lose a lot of the CO2 to the atmosphere before you
titrate it.   I agree with Karen Randall's comments about excessive
concern about analysis results.  Within a pretty large range, the plants
and the fish do not care what the CO2 concentration is.  If the setup
is working and reasonably stable, there is no point in doing lots of
measurements and trying for great accuracy.


-- 
Paul Sears        Ottawa, Canada

Finger ap626 at freenet_carleton.ca for PGP public key.