[You can buy "Daylight" bulbs at Lowes and Home Depot. One sellse Sylvania, the other sells Philips. They come in 48" lengths, and are less than $5 each.
The IceCap balllast will overdrive the bulb, but that is okay because you only need it to last 6 months anyway. I had two over my tank and it was too bright. Now I have one 6500, one URI actinic, and one URI 50/50.]