What algae is this?

[iambannana]

What algae is this? its overtaking all my plants. and how should i get rid of it?
Also, i dont really know much about planted tanks, i just bought plants and put them in, there is some sort of special aquarium dirt under my gravel though, but some plants seem to be growing well and some just die after a little while. do i need co2 or fertiliser? my lights are 4x58w t8, 2 are blue one is white and one is really white and the tank is 250 litre. thanks!

 

[aqua_chem]

What do you mean by special aquarium dirt?

 

[iambannana]

i cant remember what its called but it was just this stuff that looked like dirt that the guy at the lfs said to put down under the gravel for the plant roots to grow in, has lots of nutrients and whatnot?