Those bulbs are fine but might want to increase the wattage. Raise it to 15 or 20 watt per bulb. Thing is, you can grow pretty much any plant with low light, it just grows slower. Needing high light is a myth.
This would be great...as I stated, I ran the 36w PC and felt that it was a little much. Make sure that you also order a replacement bulb at 6700k, because the one they send with the fixture is 15k.
I would probably come to terms with your hairgrass dying for now until you are ready to meet its needs in both lighting, co2, and once those are accomplished, nutrients.