dont use blue actinic bulbs with CPs. just as they are useless in planted tanks, they'll be useless in growing CPs as well. you should aim for anything from 4000-10,000 K range. there are people who do like to mix up different combinations and ratios of bulbs, but that ends up being expensive. the most popular and readily available bulbs are the 5000K and the 6700K bulbs.