On a 5,400 gallon pool, a gallon of plain 6% household bleach will add about 12 ppm of free chlorine.

The OTO / phenol red 'dye' kit is MUCH more reliable than the test strips usually sold today. However, there's no 'cheapie' way to measure CYA (cyanuric acid), plus if you run your chlorine levels correctly, as a function of your CYA level, you have to be able to measure higher levels of chlorine than you can easily do with OTO.