Algae or scum ?

Started using PMDD (old recipe) about a month ago and since then I had a
minor outbreak of algae of some kind. I have 2 MH ( a 4300K and a 5500K)
over a 90 gal. tank with manual CO2 injection. It is dark green and forms a
film or skin-like that can easily be sucked off with a turkey baster. It is
usually found on slow growing plants like Java moss and Java fern. Can
anyone out there tell me what it is ? Is it cyanobacteria ? Other than that
water quality is good and other plants are growing great. Another question;
my red plants are not red. Will a 6500K or a 10000K MH lamp bring out the
reds ? I have a 4300K MH lamp because it is cheaper and that's what was
reccommended to me for freshwater plants. TIA.