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What one dose does
PARAMETER
1 g / 100 L
Iron
+2,280 ppb
To raise iron by 1 ppb in 100 L: 0 g.
How it’s used
Commercial ferric citrate is a variable hydrate (~16-21% Fe); ferric AMMONIUM citrate (16.5-18.5% Fe) also adds ammonium. Use the label's %Fe rather than the theoretical 22.8%.
Cautions
• Same iron cautions as ferrous gluconate (algae fuel; small frequent doses).
• Ferric ammonium citrate contributes ammonium; avoid in nutrient-sensitive tanks or account for it.
• RHF has described making iron citrate from iron(II) sulfate + sodium citrate; that route also adds sulfate/sodium.
pH effect: neutral at dose.
Sources
Commercial ferric citrate is a variable hydrate (~16-21% Fe); ferric AMMONIUM citrate (16.5-18.5% Fe) also adds ammonium. Use the label's %Fe rather than the theoretical 22.8%.