I have a couple of bottles of Phos Free and one bottle of Pool Perfect. I bought and used them before I found TFP. Other than very high CYA, go figure, my pool has been algae free and clear. I am switching to BBB, hampered only by high CYA levels and the reality of not draining 6000 gallons in a desert environment. Might these two additives act sort of like an extra filtering agent in my cartridge filter, much like DE in a sand filter, or should I just dump them?