Check the listing for details. 🌸Spring Special🌸 (15) Water Lettuce Koi Pond Floating Plants Algae Shade 2-4”. Condition: New. Listed at 33.66 USD. Each plant carries its own inflated leaves as ballast and the root are left to free float below the plant. These roots not only take up nutrient but provide surface area for biofiltration and add to the diversity of small aquatic animals that eat other helpful nuisances such as algae and excess bacteria.