How to keep plants down, and What is this????

I have a 29g that has an overgrown pl*co that continues to uproot
everything, but it's more my fault that his... He's too big, I would like to
get a bigger tank, but just got married and can't afford it, so we'll be
keeping him for a few more months, or until after winter and give to a
friend with a 450g pond....

Q: How do you keep a plant in the gravel, with a fish that is so big, every
turn he makes pulls it up?
A: Clay/TerraCotta pots 'could' be an answer, but then what do you put in
with them, just gravel? how about some clay, or some dirt that has been
un-ferted?

Q: Is there a way to take dirt from your yard, unferted, and put into your
aquarium? not potting soil, not anything special, just a little dirt...

I've got two Anubias, that recently developed a case of black brush algae...
had to take the entire tank apart to fix it, but now I've got some little
patches that came back, and I'm not sure if that's what it is.. it's small,
I can live with it... anyone care to take a look? bad picture so it
probably won't matter anyway....

ok, that's it for now.. I'm all typed out...