Plants respond well with lengthy lighting hours, but that comes with a price too, algae. My tank gets indirect sunlight but I can tell they don't photosynthesize because the leaves folded once tank lights are off. I use to have my lights for 8 hours with good growth but had some algae. Now I have them on for 5 hours and ambience light thereafter, even BBA starts to go away. I've rather have slow growth, less algae and less trimming. You don't need airstone as long as there's surface agitation from your main filter.