So... how effective are they compared to say a 4000k range bulb? Should i replace it with a regular one? Also i was at a pet store and they were selling 50/50 bulbs, not sure what they were called (actinic or something?) but half the bulb was blue. I was thinking they were to create the blue effect for saltwater, but i may be wrong. So which of the three should i choose, my current soft white CF, regular CF, or 50/50 CF.