I believe it has lots to with the tap water, I agree the lighting might not be optimal but there is more going on than that. I'm told by the lfs manager who's been breeding Cichlids in this water or years told me anyone who has a non planted tank has cichlids or community on single tubes with low photo periods to prevent algae. He also said anyone with plants uses RO water because the city's water isn't good to grow them and the parameters fluctuate too much. I want to attempt to address this issue first, furthermore in the previous city that I lived in the water was much more stable and in tanks with more light than this and no CO2 including this one I had far less to no issues with algae as long as regular maintenance and proper nutrient levels were present.
75 gallon Tanganyika Community Planted