Man I'm going to start sounding like a sales rep from Salifert .......
But this is exactly why I use Salifert calcium and alkalinity test kits.
With other kits - as I was doing the titration, adding the reagent drops one by one - the color would sort of start fading towards final color I was waiting to see. It was not a distinct color change. I always saw ;
Alkalinity - bluish to sort of bluish/pinkish.
Calcium pinkish to clear blue - sort of.
But I was never 100% sure of the final reading, due to this slow fading of colors, and never new when to actually stop adding drops.
Salifert test kits for calcium and alkalinity on the other hand are very easy for me to use.
As you add the drops and approach the final point, you begin to see the vial liquid turning color and with the VERY LAST DROP - BOOM !
Complete color change in the vial.
Look at the syringe - get your number - look at chart in the instructions - and you got it !
Salifert - try it on your next test kit - or treat yourself and go get one now.
It shouldn't be this hard to get a good reading on our tank water - ya know