The dipsticks are accurate, but do have limitations:
1. If they ever get exposed to too much humidity, they won't work right. This means keep them tightly closed and refrigerated - only remove one strip at a time and immediately recap the vial. Still, after a year I wouldn't necessarily trust them.
2. Make sure the kit has the range and graduations you need - if you want to measure 0.5ppm phosphate, a kit with a low phosphate of 2.0ppm does you no good.
3. They do tend to be more expensive on a per-test basis than liquid tests.
72g bowfront planted, CO2, 2x - T5HO, Eheim 2213 and 2013, red tiger lotus, vals, java fern and moss, crypts, swords, mbuna tank: Yellow labs, Ps. demasoni, clown plecos, SAE's.
10g mini-reef. 16lbs LR, green mushroom, star polyps, wagon wheel polyps, purple mushroom, candycane, hammer, other zoas, CUC.