Hornwort. It grows faster than anything I've seen (on 1.6 WPG!), it gives
out chemicals that kill algae, it's a nitrate/nutrient sponge, it can easily
grow over 2' tall, and it does not need to be rooted. In fact, if rooted,
it just anchors itself and continues to draw nutrients from the water. It
looks like Cambomba (sp?), but is about 1,000,000 times easier to keep.
It's also very hardy to different temperatures, pHs, and kHs. It's truly a
wonder plant!

Tony