Now look, there are many ways to define alkalinity, but a darn good test kit/method should be in place if you plan on doing this right.

Folks from years past screwed up NO3 and PO4 using cheapo test kits and poor assumption. About 11 years Steve Dixon got fed up and adopted the Lamotte abnd Hach line to get around this issue. I followed suit and then questioned whether the Lamott and Hach kits where accurate as well.

Here's a digital Alk test:

Hach - Alkalinity Test Kit, Model AL-DT, Digital Titrator, 10-4000 mg/L, 100 tests

Here'a a cheaper HACH test kit:

Hach - Alkalinity Test Kit, Model AL-AP, Drop Count Titration, 100 tests

Here's the Lamotte:
Alkalinity Test Kit

Look, don't monkey around all hodge podge here, do it right and then you can feel better about it.

The Chemistry Section: Alkalinity

And for the UK folks: Hanna Instruments HI-3811 Alkalinity Test Kit

1ppm ain't bad

Hanna makes a one for the USA yanks as well.

Regards,
Tom Barr