I saw this new product at a local store. It's made by HTH...HTH Weekly Power Pod - 3 in 1 clarifier, enzyme cleaner and phosphate remover. It comes in one of those pouches that dissolve in water (like a laundry or dishwasher pod).
Ingredients listed on package are zirconium acetate and Pepsin A.
What is zirconium acetate and isn't Pepsin A for upset stomachs or something?
I also found this patent which sounds a lot like this product.
(by the way, my pool water is fine - I don't use or plan to use this - I just noticed it as a new product at the store)