HOB Aqua Fuge

I have a small HOB Aqua Fuge with the 18 watt light that came with the CPR Fixture and I have chaetomorpha inside. I run a 12 hour reverse light schedule opposite to my main lights. This Aqua Fuge only 6 weeks old and I have brown diatom algae on the inside of the fuge that grows. The Chaeto is not growing much at all. WHen it was new the Chaeto was very gren now looks kinds drabby in color. I have a aquaclear 20 power head inside also. I use to have the Chaetro inside of a in-tank refugium with great success in terms of growth. I can not understand why the chaeto is not growing much if any? COuld it it does not like the lighting. The bulbs are 10,000K. Before these bulbs I had the 6500K buls with still no growth and Chaeto that looked like it was dying. I also have one piece of LR in the fuge and thats it. Any help is appreciated. The main tank has just a little hair algae that is growing(very little) PH is 7.8-8, Alk is 9, Calcium is 420 SG 1.025 atemp is 78 No Nitrates, nitrite or ammonia
Adam

 

for starters your ph should be between 8.1 and 8.4.. but your light it's probably fine

 

When chaeto has good light it can lighten in color, and dark green where it is shaded more. So your color of chaeto, if purely a lighter color, is not by itself a bad sign.