Salvinia

Salvinia is a plant that is perfect for goldfish it absorbs loads of nitrates by propagating rapidly and goldfish tend not to eat it. Salvinias surface is covered in a small hairlike protrusion that give it a really unique look.

Care:

This plant is tough as nails as long as the tops stay dry to avoid molding they will grow and grow.

Temperature: 60-82°F

Lighting: Low-High 

Fertilizing and CO2: CO2 is unnecessary, but they do enjoy liquid fertilizer although the waste from your tank will likely be enough.