I have a 5 gallon freshwater aquarium with fake plants with a 15 watt incandescent bulb in it and i'm getting bored of the dull colors it produces. I went searching for bulbs and found some fluorescent and compact fluorescent bulbs. At walmart i found a 20W fluorescent bulb for $5 and at petco i found a 10W compact fluorescent for $14. the compact fluorescent has a white and blue bulb on it. will the more expensive bulb look any better? what's the difference between the two? thank you.