Hi Barry, I like the fixture a lot. I love the slightly blueish tint the tank has (my fixture has one 10K bulb and one actinic bulb), fish colors really "pop". In a room with 3 other tanks that have 6500K and pink grow bulb tanks, makes the other planted tanks look real yellow. The tank I have the Deep Blue fixture on is a 75g, 21" high, and I have the same concern you do, I'm going to give it a go with the 10K and actinic light. All I have in the tank is anubias, java windelov and a small crypt, I'm hoping the 10K will be enough light. Below is a pic of the tank, staying cycled with tetra's, waiting for the Mbuna to arrive.