stusclan
Aquarium Advice Activist
Did my yearly changing of the bulbs - even though I put a new bulb on the sw tank 4 months ago (I remember better if it's at the beginning of the year. So my question is, what is the difference in a 40W 10,000K bulb and a 40W 18,000K bulb? I put the 18,000K on the tank, but don't know the difference. Lighting has me confused. :?