Best Iron-Rich Foods for Freshwater Fishs

Ranked by iron content among foods safe for freshwater fishs in the Creature Feast catalog.

Bloodworms per 100g freeze-dried: ~12mg iron (heme form, high bioavailability) Bloodworms are the richest iron source among common aquarium foods, which is fitting since their distinctive red color comes from hemoglobin — the same iron-containing protein in fish blood. This heme iron is absorbed far more efficiently than plant-based non-heme iron, supporting oxygen transport through fish gills and throughout the body.

Spinach per 100g blanched: ~2.7mg iron (non-heme, moderate absorption) Blanched spinach provides non-heme iron that contributes to iron status in herbivorous fish. While less bioavailable than the heme iron in animal foods, the vitamin C naturally present in spinach helps convert some of it to the absorbable ferrous form. Limit feeding frequency due to oxalates.

Spirulina flakes per 100g: ~28mg iron (highly bioavailable algal form) Spirulina flakes contain substantial iron in a form that is relatively well-absorbed by fish. The iron content supports hemoglobin production, which is critical for oxygen delivery from the gills to every tissue in the fish's body.

Peas per 100g shelled: ~1.5mg iron (non-heme) Peas provide modest plant-based iron that adds to the overall iron intake when fed as part of a varied diet. The iron in peas is non-heme, but the presence of vitamin C in the same food enhances its absorption.