Okay, I now have NIST referenced alkalinity solutions. They are high concentration, 25,000ppm as CaCO3 measurment from Na2CO3 and 10mls. So one will make 3.49944 liters of 4 KH solution: 71.44ppm.

Since the accuracy is high at high concentrations, the dilution downstream errors will be very low.

I have a nice Volumetric flask as well and some smaller ones and pipettes that are accurate to 0.01ml for the topping off part or I could snatch a micropipette from work.

But I do not think I need that mucn accuracy, this will get me well below the 0.1ppm range and that will not influence CO2 much(much less than 1ppm).

Greg Watson might sell it also. We shall see.
Given they are small etc and make a lot, they would be well worth it since most folks will have to buy a scale, and deal with the mixing and other unverifiable issues.

This way it's a lab grade solution you dilute.
Vaugh, you want 1 liter of certified 4KH solution?


Regards,
Tom Barr