Bob Vivian said:Any K rating will grow plants. 5500k or lower is, IMO, too yellow/green for my viewing purposes.
I prefer 6500K's. The 10000K's are whiter but still pleasing to the eye.
The Coralife 6500K's have great color but are expensive. Hamilton's 6500K "Superbrite" Day bulb is less but shows too green for me.
Hope that helps.