When the chlorine is dark yellow or beyond, your pH test is NOT reliable. Only test the pH when the chlorine is lower. If you have a non-Taylor pH test, you can only test up to chlorine = 3.0 or so. With Taylor, you can test up to 10 ppm. There are exceptions, but I'm not going to cover them here. The bottom line is, if your pH was OK before you started adding bleach, it's still OK, as long as bleach is all you added.