Dichlor will continue to add more CYA which you really don't need since a CYA of 50ppm is a good level. However, if you have no liquid chlorine on hand and don't want to make a Walmart run to get some bleach, it is ok to use dichlor for a little while as long as you are aware that the CYA will continue to climb and are ok with that.

It is also ok to add some muriatic acid now to drop the pH a little but first please read the tab in my signature about using muriatic acid safely. Wait awhile after the addition of the acid before adding the bleach or dichlor and you will be fine.