There is no way to know how long it will take to break down that algaecide. I wouldn't suggest adding the defoamer. Sometimes you create a vicious cycle -- adding product #2 to fix the problems caused by adding product #1, adding product #3 to fix the problems caused by adding product #2, ........

Give the chlorine time to clear it and keep your filter running. What type and size of filter do you have and what size of pump?