I dont think so.....Phosguard is obviously a phosphate remover but I believe Purigen just polishes the water somehow. That said, I dont understand the science behind the purigen but I am pretty confident that it makes my water clear as day.
PhosGuardâ„¢ rapidly removes phosphate and silicate from marine and freshwater aquaria
Purigenâ„¢ is a premium synthetic adsorbent that is unlike any other filtration product. It is not a mixture of ion exchangers or adsorbents, but a unique macro-porous synthetic polymer that removes soluble and insoluble impurities from water at a rate and capacity that exceeds all others by over 500%. Purigenâ„¢ controls ammonia, nitrites and nitrates by removing nitrogenous organic waste that would otherwise release these harmful compounds.