To work on the algae I would cut your lights back, do some additional water changes and cut the feeding back as well.
I also strongly agree that the tang needs a MUCH bigger tank, even if he is small right now. That tang in particular needs a 6 foot tank just for starters.
In addition, that anemone should not have been added so soon. Clowns won't host a condy and those nems can actually eat fish and they get huge normous. lol I had one and returned it, took up nearly 1/3 of my 30g tank when I had it.
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.