Lanthanum salt phosphate removers excel at clouding pool water and clogging filters. They are also very good at removing money from your wallet. Otherwise they really are not that useful and certainly not needed.

If you are worried about your pool turning green while away for a week at a time I would strongly recommend adding borate to 50 ppm to your pool. I have it in mine and go away every summer for 10 days to a few weeks, live in Florida where pools turn green very fast, and the worst I have ever returned to was a slightly cloudy pool. ( And I shut everything off when I go away so there is no circulation.) All I need to do when I get home is shock and I am good to go the next day.