The increased flow should help a lot. waiting and seeing can't hurt. If you currently have no algae problems, why would you try to cut your light even more? It's good to take things cautiously so you can figure out why they happened, but remember you do know how to defeat BBA if it comes back. I'm a fan of really high light, but I'm a miser with my ferts. You can have all the light in the world and algae will not grow if there are no ferts in the water. Plants can use the ferts much more rapidly than the algae can (although algae can crack out nitrogen that the plants cannot), and plants can use the light much more efficiently than algae can that is why plants can do fine on a 2 hour photo period if it's bright enough but algae will suffer. The best photoperiod for algae would be 24 hours on.
With high light and unhealthy plants you will get algae even if there are no measurable nutrients in the water. Algae consume minute amounts of nutrients, and are able to get them where plants are starving for lack of nutrients. It is healthy plants growing as fast as the light intensity is driving them to grow that tends to keep algae away. It isn't a competition for limited nutrients, but exactly what it is seems to be a mystery.