Yes it is, From about 8:30am to 3:30-4:00pm (this time of year) It get a lot of natural light. I've considered that as well.. My initial concern that was the algae was brown.. then I researched and learned it was diatom.. researched some more and found out
nitrate and phosphate can cause it.. Then all of these fine folks filled me in that its probably just the tank doing its own thing..
The amount of sun the tank see's in a day, I expected to need a fleet of BN pleco's. But until now, I was wrong.. its just starting on the tops of my plants..