my val gigantea could easily take over my 29 gallon if given about 2 months. I started with one, dying, mostly melted blade of grass and within a week, it started growing leaves that were up to about 6 feet long. When it feels frisky, it can throw out 4 or 5 runners in a week all of which grow into 5 or 6 foot long plants. They wouldn't be so bad if they didn't block so much light. But it was my first plant. I'm kinda attached. Every month or so i remove probably a half dozen plants and leave just one. Not the biggest pain, but it's annoying.
