Its time to replace my bulbs in my four bulb 48" aquatic life fixture, and have no clue what combination to use. I know I could go to the fish store i always use and just let him put whatever he thinks is best, but I think i can get better bulbs for a cheaper price if I do it myself. This is my first time changing these bulbs so currently just have what it came with, 2 10k and 2 actinic, I think. I have a 75 gallon with mostly lps, but would like to get some sps in the near future. Any help/suggestions would be appreciated, I am ready to buy, but trying to be patient and do some research.