WHAT IS THE BEST FLOATING POND PLANT? - The #1 floater, based on how well it filters the water and how fast it grows, is the WATER HYACINTH. This floating plant can really clear water, and quick. The only drawbacks for this plant is that it can be invasive. Later in the season it tends to grow so quick that people will throw it out by the trash bag. The other drawback, in my opinion, is that it only blooms a couple times a month, however, it does have nice purple flowers.