Re: ph Testing

To: aquatic-plants at actwin_com
Subject: Re: ph Testing
From: Daniel Marsh <dmarsh at premier1_net>
Date: Thu, 16 Jan 1997 22:19:13 -0800

Augustine wrote:

> When using the Hach CO2 test kit, care should be taken when removing the
> water from the tank.  When you remove the water try not to pour it into the
> test bottle.  I have used a plastic measurement syringe successfully for
> this purpose.  You are measuring carbonic acid.  Your end point is the
> first point at which the solution turns a light pink.  I use a reference
> solution of DI water in a second test bottle.  I place both bottles on a
> white surface, side by side.  The endpoint is obvious when you compare the
> two bottles - even though it is light in color.

Your suggestions for reading the CO2 test were very helpful, especially
using the reference solution, it is _very_ light pink but I can see it.

We sent to Hach for their 7.0 buffer to test the phenol red reagent
against, as per their instructions, and found it to read 7.0 perfectly.
However we found that our ph meter read the new buffer @ 7.2 ,which
sheds some light on the problems we've been having :-).

Our test results are now starting to make sense. 

Thank you very much for all your suggestions and help, they are greatly
appreciated.

Rebecca and Daniel Marsh
In currently stormy Gold Bar, Washington where the tap water content
changes almost as fast as the weather