Join Date: Jun 2013
Location: Gilbert, Arizona
Don't buy a new light! That's clearly NOT your problem, 10000k is just as effective for our purposes as 6700k or similar! Assuming your light is made up of 1w LEDs, you should be getting a solid 15w of usable light.
If possible, I'd turn off the blue lights, they're not really helping anything, the 460nm light is only really feeding one of the main forms of chlorophyll, and without hitting the peaks on at least A and B it doesn't add any reasonable growth.
Your tank should work for low light plants. There's probably a lack of vital nutrients (you look like you have a very light stocking level) which may contribute to poor growth/plant death.
People are too often merely stating an assumed truth from flawed observation.