in my opinion 6500k or lower k bulb will more readliy grow algae than 10-20k bulbs. People that grow plants often use 6500k bulbs. A 6500k bulb is considered a grow bulb where as a 10k or higher bulb is considered a blooming bulb. The 6500k make plants long and gangly where as the 10k make plant more dense and bushy. I am not sure but I am guessing that the 6500k spectrum transfers more energy. I had a 6500k 400w
MH and everything grew like crazy, but it was all yellow and that wouldnt do. What are your lvls in the tank, espically
nitrates/phosphates? Having measurable lvls of these will promote algae growth and may negatively effect other life in the system. In a small nano tank I would suggest making a small
refugium. I would place the
fuge above the nano tank and use a small pump/powerhead to pump water up to the small
fuge and gravity feed the water back to the nano. You dont want high flow so a small power head would do.
