Water Foaming and Cloudy after Adding Bottle of ALgaecide

I have a 15000 galloon free form plaster pool, saltwater, that is 1 1/2 years old. My water chemistry has been spot on for all levels.

My pool guy advised when doing pool school to add whole bottle of algaecide every 3 months as routine maintenance. I have had no problems with algae. over the past 18 months, I was using an algaecide treatment made by Regal, Algaecide 60, which is considered a polyquat.

Just yesterday, I started a 24 hour superchlorinate setting and used a different algae product from Walmart, HTH Super Algae Guard (linear quat, started with "alkyl"). The water is very cloudy and is foaming quite a bit. I have NEVER had this reaction when using the previous algaecide. I called HTH and they said only way to get water clear and no more foam is to drain and refill 1/3 to 1/2 of the pool. I do NOT want to do this so if anyone has any suggestions or advice, Im begging for help!

Thanks in advance.