Best Vitamin C-Rich Foods for Freshwater Fishs

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

Peas per 100g shelled: ~40mg vitamin C Blanched peas are an excellent vitamin C source for freshwater fish and one of the most widely accepted vegetables across species. Shell the peas and blanch briefly to soften — the natural vitamin C is heat-sensitive but a quick blanch preserves most of it while making the pea digestible for fish that lack strong grinding teeth.

Broccoli per 100g blanched: ~65mg vitamin C (reduced from ~90mg raw) Broccoli florets blanched until just soft provide a strong vitamin C boost for herbivorous and omnivorous aquarium fish. The vitamin C in broccoli is more heat-stable than in many vegetables, so it survives the brief blanching needed to make it palatable. Offer tiny pieces that fish can nibble over several hours.

Zucchini per 100g blanched: ~12mg vitamin C Zucchini slices are one of the most popular vegetable supplements in freshwater fishkeeping and provide a gentle vitamin C source. Drop a blanched medallion weighted to the substrate and watch plecos, corydoras, and snails devour it. The mild flavor means even picky species accept it.

Spirulina flakes per 100g: ~10mg vitamin C (more stable than ascorbic acid in flake food) Spirulina flakes contain naturally occurring vitamin C in a stabilized form that resists the degradation common in stored fish foods. Since vitamin C in standard flake food breaks down within months of opening, spirulina-based foods serve as a more reliable long-term source.

Kale per 100g blanched: ~40mg vitamin C Kale is vitamin C-dense but must be blanched thoroughly and offered in very small pieces for aquarium fish. It is best suited for larger herbivorous species like silver dollars, larger plecos, and goldfish that can handle tougher plant material. Remove uneaten pieces after a few hours to prevent water fouling.