algae colour

[ocean rock]

hi all
can anyone tell me why the algae has gone like this after 2 month?
http://i257.photobucket.com/albums/hh210/recoilphotos/DSCF1099.jpg
stewart

[SantaMonica]

Old bulbs

[ocean rock]

new bulbs i month old just moved from 14w up to 23 w .

[SantaMonica]

I thought that was the screen.

Pics of the everything before and after cleaning.