[angiemouki]

As mentioned above, I am doing an experiment to measure the percentage of calcium ions in milk of different fat percentages to find out which has a higher amount of calcium ions.
I am also using EDTA to form a complex with the calcium ions.
Now I am very confused about what indicator to use, I did my homework and it seems that patton and reeder's is a variant, but so is hydroxy naphthol and phenolphtalin, I would like to know which one is best to use and the reason for that.
thank you

[Mitch]

I would go with whichever reagent your laboratory already has.