Salvinia Minima
Check out it's awesome looking hairs. This plant has a sort of "Fuzz" or "hair" on it which we believe goldfish don't like the taste of.
This is a FAST Nitrate absorber. Like all floating plants, salvinia lives at the waters surface, ABOVE the water line where it has more access to readily available CO2 and light, making it "Work harder" for you. This is also a great plant to block out excess light and avoid algae with it's ability to absorb nutrients faster from the water column than underwater growing plants.
With each portion, you will receive a half of a dollar bill portion. (Cut a dollar bill in half. They will cover that.)
UPDATE: We have been told by Luke's Goldies that GOLDFISH DON'T LIKE THE TASTE OF THIS PLANT.