While I'm asking about plants, can I ask if I need to add anything like Seachem Flourish? I haven't been adding anything as I was told it wasn't necessary, but now I'm really curious since the petsmart people didn't really seem to know what they were talking about. They do get direct sunlight during the day. The tank is not right next to a window, but we're in a small townhome and the tank is across the room from two windows, so it does get sunlight, along with out led bulbs. Other than light, I'm just curious if I need to actually add anything to the water.