[west9491]

i'm sure that the iron properties in flourite substrate doesn't last forever, but how long should it be before is should be replaced???

 

[Rex Grigg]

Forever. In human lifetime terms of course. Since the iron is bound up in the substrate there will be iron pretty much as long as the substrate exists.

 

[florafan]

Does that mean that one does not need to dose iron, ever?

 

[Rex Grigg]

I did not say that either. The iron in Flourite releases very slowly. So in "fast" tanks you need to dose iron.