What color are the foam and bubbles? Can you post a pic?
A lot of different meds and water treatments can cause foam, and sometimes cloudy water, but after 2 water changes, and carbon in the filter, it should have dissipated by now.
150g long S Amer cichlid; 90g C Amer cichlid; 90g Malawi cichlid; 40g Tanganyika cichlid; 29g "Shellie" cichlid; 29g Pea Puffer. 6,500g koi/native catfish pond; several smaller ponds