I am setting up a 108" long 24" tall and 26"deep tank. I bought Aquaticlife 48" 4x54w T5HO. I had originally just wanted to buy 1 set so 8 bulbs. The fs said not enough light for that tank and convinced me to buy another set for a total of 16 bulbs. I plan on a couple inches of substrate and will have a carpet and other plants and fish. I have read lots on the lighting and could not find articles for large tanks. Thanks for any info.