I've actually got an LED bulb but it was surprisingly weak. How many watts do you suggest.
Michael Hoaster: 5-65K isn't blue though? Are you saying 5-65 instead of blue? Or go with blue for macro algae. I was under the impression macro did well under the kind of light that grows coral...but that's why I was asking to make sure.
5000-6500 is considered daylight-little to no blue. So yes, instead of blue. Micro algae, which I assume you don't want, can make better use of blue light, allowing it to access iron in the water. So, I was suggesting a daylight spectrum light, rather than a bluer one.