I have a 37 gallon aquarium that is 22 in tall. Currently, I've got a couple amazon sword plants growing under t-5 lights. My question is what bulb is best. I see 6700k lumens advertised on the box as being the best for plants, but am I correct that 10000k is better? I'd like to upgrade my lighting to a dual light fixture and the one I"m currently looking at comes with a 6700k bulb and then a color enhancing bulb. If I really want my plants to grow do I need to swap the 6700k bulb out?