HI, and welcome to the forum!!

Did you add any type of chemical just before the suds started? Have you added any algaecides other than polyquat, which commonly cause foaming? How about the use of tile/vinyl cleaners or any other cleaning product other than chlorine? Is it a chlorine or bacquacil pool?

If you'll give us more information about your pool, pump/filter, and chems you're using it will help us give you better answers to your question....