My understanding is that it removes nitrates.. so this is a no go.
Right from the lips of Seachem.
Purigen® controls ammonia, nitrites and nitrates by removing nitrogenous organic waste
that would otherwise release these harmful compounds.
Purigen’s impact on trace elements is minimal
Purigen® is specifically designed to be an organic scavenging resin
Purigen® generally ignores simple elemental compounds
, having an extreme affinity for nitrogenous organics
Fish poo, mulm, dead plants matter, etc....
This should all be removed and not allowed to become dissolved organics.
Purigen can still catch all the stuff we can't see.
As for the compounds we dose, would you rather wait for fish poo, mulm, etc to go through the nitrogen process to provide nutrients or dose with nice pure compounds?
I would also imagine that most Phish
waste is in the form of liquid, quickly becoming a form of ammonia and providing plant uptake similar to dosing urea unless the bio filter gets it first.