Red Algae

[Lobster Boy]

I have a 52 gal tank, started in early Dec/2001. Approx 30 lb rock, recently due to over feeding I lost 75% of my fish. I tested and found high levels on all 3 of the standard. I did a 18 gal water change and thing have now become more stable. Levels all back down and the remaining fish seem to be happy. I do however have a heavy film of red covering the entire glass, And it appears daily.

Any suggestions would be a great help. Or will this just go away.