Bleaching/dying red algae..help!

[SteveConn]

I bought some red halymedyia <sp> few weeks ago and now it looks like its dying in my sump. I initially had a crappy 3500K CFL lighting the sump (fine for the green algae), and have since updated it to cree white and royal blue LEDs. Lights are on 13h per day. My nitrates are undetectable and PO4 at 0.04ppm. Calcium and Alk are good for SPS
In the last week or two , the algae has been losing its color and is now pale... almost dead looking. It initially has grown, but now looks pretty awful..loose and pale, not the deep color it was initially.
Green algae is doing fine as ever. Too much nutrient competition?

Any advice?

Thanks

Steve

[SeaHorse_Fanatic]

Switch back to the old light.

[reefwars]

No nitrates is a part of it to, what little you get is being taken by the green, I keep both and I find the red grows fast and stays bright red I have it under 5500k bulb and 10ppm nitrates zero phosphate. I have high flow through my sump. And its in with several other types of macro.

Without some sort of food the red will starve its not as Hardy as cheato or other green halimedas

[SteveConn]

Thanks for the input so far.
The LEDs were added to add more spectrum because the algae was dying.

The sump is fairly low flow. Water comes from the phosphate remover reactor. I can increase my flow.
I took filter socks off for a few days in hopes of improving nutrients, but still see a decline in the algae.
Could also remove the cheato for a bit and see what happens.