Re: Water Chemistry Reference
I'm at my wit's end again (I can hear sereral of you saying 'yea, so what
else is new?), and as usual, the reason is water chemistry.
Just before Christmas, I ordered a number of LaMotte and HACH test kits.
The LaMotte kits arrived with no problem and I was very impressed with
them. Today I received a package which I was hoping would contain a HACH
Calcium and total Hardness Kit. Unfortunately, the supplier made a mistake
and sent me the HACH Alkalinity Kit (AL-AP MG-L) by mistake. While looking
at the instructions which came with the kit, I notice that, unlike the
LaMotte Alkalinity Kit which measures Total Alkalinity, the HACH kit
measures both phenolphthalein alkalinity and total (methyl-orange)
alkalinity. Both measurements are in units of mg/l of CaCO3.
My confusion is caused by uncertainty over just what is being measured by
each of these tests. As I understand it, Alkalinity in freshwater is caused
by basic ions (predominantly but not necessarily exclusively HC03- and
CO3--). Neither the LaMotte nor the HACH Alkalinity Test Kits give much
background as to what is actually being counted by their titrations.
What is phenolphthalein alkalinity and how does it differ from total
alkalinity (I measured my tank's water with both test kits and while the
LaMotte and HACH test kits give identical readings for Total Alkalinity,
the HACH kit indicates that my water has zero phenolphthalein alkalinity.
I'm not concerned for my tank's health - everything is going fine, the
plants are growing and the fish are eating well. But my curiosity is piqued
- I like to be able to understand things.
Can anyone recommend a comprehensive book on Water Chemistry as it applies
to freshwater aquaculture? George Booth has made several references to one
published by HACH but they advised me that it is no longer available. Are
there any others which go from A-Z, in detail? I have laid out all of my
aquarium books and marked their sections on water chemistry. The
differences are much more apparent than the similarities so I don't know
which, if any, to believe. There must be a standard reference in this area.
If anyone knows a good, solid reference book on water chemistry, I'd love
to get the name and publication info so that I can answer my own questions.