I use the red sea test kit with pretty good results. Colors aren't too hard to tell and if you're confused, you can redo the test diluted with 5parts distilled water to help narrow down your exact number.
20g platy, , 2 x 10g shrimp, 3 x 20g shrimp, 7.5g shrimp and 1 great dane/mastiff puppy.
Sump Pimp #2
My Tanks and my shrimps