Do These Work?

Yep, but you can buy a huge bag of poly filter for around $4 at walmart.

or petco

How does the walmart stuff remove heavy metals and all forms of phosphate?

This is not the same as the filter floss/walmart stuff and yes, it does work!

^^^Agreed not the same...and yes Poly works great on metals...just may take 2 to 3 months to remove all trace. It turns colors depending on what its removing