Algae is due to an imbalance in your tank. you may have too much light/too much nutrients or both in your tank :) you can reduce photo period to deter algae growth. a little excel will also kill algae.
asian ambulia (Limnophilla Sessiliflora) is a federal noxious weed, make sure that it does not end up in in the wild. if you want to throw away trimmings discard it in the trash...
It was an interesting story how this became a federal noxious weed. I think it was being invasive in a certain water way, and some geniuses decided to eliminated it by hacking the patch of limno Seissiflora to pieces. Every single piece then grew into a new plant and the invasion escalated to uncontrollable levels....and so they banned it.
So what does having a federal noxious weed mean? It's perfectly fine to keep in in our tanks, but it is illegal to move it anywhere else without a license to do so. "Moving" in this case includes the giving away, shipping, selling, dumping it in the wild >.> you get the gist =D Whoever shipped it to you wasn't being very responsible ;)