Well youre doing proper water changes, no doubt about that. You might wanna cut the feeding back a bit, I know it's hard especially with a scooter. lol If you don't have any corals you could do a a black out period and cut the lighting way back or off even for a few days. That can help you get a handle on the algae.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.