Is a 6400k bulb good for a low-light, low-tech planted aquarium? If so, should it be paired with anything else to get a better quality light spectrum? I ask because a 24" T5 HO 6400k Sunblaster bulb is $10 each compared to $25-ish for a 6700k aquarium plant bulb. Thanks. :)
They are perfectly fine. I run the Sunblaster bulbs on most of my planted tanks. :)
Plants will grow under with spectrum between 2000 - 10000K. Pick your color spectrum depending on what's pleasing to your eye. 6000-7000K is considered daylight spectrum, a great choice for low light, it will give you the most natural look. Go lower and it becomes more yellowish (is more for the living room), go higher if you want to see more red (only really good for high light tanks with red plants).
Thanks for your help, Robert. I appreciate it. :)