The FasTest kit has been the one I've used for years, but if you have problems reading it, try another. Salifert and LaMotte are excellent kits, and the Red Sea kits are good too, and includes the alkalinity test in the ph kit. If you really want to be accurate, invest in a ph meter. If you have a reef, you will really be glad you have it. You can get a good one for about $89. If you decide to get one, I recommend the type that operates all the time. The "Pen" type is more trouble. I have one, and I never trust it since you have to calibrate it every time you use it.
Sonny