Magnesium Test Kit

I have a Red Sea Magnesium Test kit (not the pro kit) that I dread using because I have such a hard time telling when the end color is reached.  It is supposed to go from pink to blue, but it turns violet during the transition.  It seems like it is violet forever and I don't know when to say it is finally blue.  I've checked fresh salt mix and I don't trust my results.  On top of that, the test has a lot of steps, so I really don't check it as often as I would like.
I'm considering trying out the Salifert Magnesium kit next.  What do you use?  Any recommendations?

 

Thank you everyone for your responses. Adam, Thanks for the link to the video. It very clearly describes how the endpoint is reached. I may be adding the titrant "C" too slowly and missing the end point. I will try my luck with the Red Sea kit a few more times. I will probably buy the Salifert Mg kit next to see which one I prefer.

 

I retested with my Red Sea kit, adding the titrant slightly faster and it was easier to determine the endpoint. Interestingly, it measured very close to my earlier measurements, which were all lower than expected (1040-1080 ppm).

I bought the Salifert kit from BRS and it arrived today. I measured twice and got 1230 ppm both times. In my opinion, the Salifert kit was very easy to use and it was well worth every cent. The results are in the right realm and less prone to measurement error.

Thanks again for your input...I won't loose any more sleep over this! WoHoo.

BTW...I also tried Saliferts Calcium and Alkalinity test kits this week for the first time and I am just really impressed. I love the precision.