Originally Posted by
srfisher17
http:///forum/post/2845186
Most phos removers are ferric hydroxide. IMO; they work well, but deplete very quickly. I use SeaChem Phosgard and really prefer it. It is inexpensive, less messy, and lasts much longer than the ferric hydroxide products. BTW; I don't believe Purigen is really intended to remove phosphate--it is an all purpose carbon substitute and mainly removes nitrogen compounds & polishes water.
Problem with Phosguard is many soft corals have been proven to react negatively to it (its aluminum oxide media which have been proven to leach and effect certain soft corals. I'd post the link but I cant here. Phosguard specifically was tested).
As far as lasting longer its as simple as ferric oxide removes phophates faster thus exhaust faster. aluminum oxide removes phophates slower thus last longer while maintaining low phophates. If you have a phosphate "problem" ferric oxide works better. If you already have low phophates and want to maintain it aluminum will last longer. Both last a relatively long time (months) if you already have low phosphate levels.
here's ELOS explanation:
Elos Filtra P FAST is an efficient phosphate remover based on IRON. In contrast to ALUMINUM base FILTRA P, this product is used to quickly remove phosphate both, inorganic as well as organic. It is completely reef safe unlike some competing products adsorbants which may leach phosphates back to the aquarium or may simply precipitate driving more phosphate onto the sand and rock and suspended CaCO3 particulates.
ELOS FiltraP FAST, should be use as a "symptomatic product". It should be used to rapidly reduce the level of phosphate. It is also suggested to use the ALUMINUM BASED formula (ELOS FILTRA P) from the setup in order to keep PO4 constantly under control