i just can't get the PH drops to work, i got 2 different brands. it's so hard for me to read the scale, the of the water changes depending where you look, if it's sunny vs artificial light for example, and the color of the background too... how can i make sure the reading is correct? i struggle a lot to interpret the color of the waterYou have a scale so you just compare. The JBL brand makes some that I can for sure put it to the nearest 0.5, and even when inbetween, you can see which way it leans. They are also 3 to 10 ph scale. More than enaugh scale.