Is My Ferric Oxide Depleted?

[Dom]

I began running Ferric Oxide to help with elevated P04 levels in my tank.

DI resin changes color when exhausted. Is there a way to determine visually if the Ferric Oxide is exhausted?

Thank you and Happy Thanksgiving.

Dom

 

[P-Dub]

If no additions to your tank, no changes to your feeding, skimmer running the same, your levels will begin to elevate again. When that happens, you know it's time to change.