test strips are notoriously unreliable, i would take those results with a grain of salt and see if you can take your water to a LFS and have them test it for you. Many bulbs in fixtures that come for plants have a spectrum written on the bulb itself, yours may be written there.
Cutting back lights might help, but regardless of what you do, you will need to remove the affected leaves on the plants and scrub the affected rocks, to try and remove as much of it as possible. Most algaes really capitalize on nitrates and phosphates in your water, phosphate testing is hard to come by at least i havent really seen kits readily on sale, but nitrate tests are very common, you may want to pick one of them up, they are fairly inexpensive and last a long time. Many on the forum use the API Master Test Kit, which will liquid test for ph, nitrate, nitrite, and ammonia. Additional supplements for the kit have GH and KH tests. Prices are usually around 25-35 dollars per kit and an additional 5 for the GH and KH.
Water disturbance at the surface is different from overall circulation. When i had BBA i found most of it to be hear the underside of my HOB filter lip and on decor furthest away from the output, both those locations get minimal circulation since HOBs have a tendency to recycle water they clean. Take a look at the locations where the BBA is worse, is there a defining pattern? If its just everywhere then its not an issue of circulation.