Long photo period... I thought mine was long at 14 hours.
If all of your light is 10,000K your plants may be doing ok but perhaps only due to overdriven lighting and the algae will take advantage of this. I would bet that you could swap out those 10,000k reef lights for 6,500k plant lights, drop the photoperiod to 8 hours and the algae would disappear.
Even with my 14 hours of light and high lighting plant lights I have zero algae... at least I've never cleaned any off of the glass, plants or driftwood other than a little beard on some vals' dead spots occasionally.