(1) New tanks will almost always have algae blooms in the first few months...
(2) You can always check out a good cleanup crew of crabs, snails, etc...
(3) or your best bet is to setup a refuguim (few benefits below)...
- Place for algae to grow
- removes nitrate, nitrite, and phosphates
- safehaven for small critters (cocepods, starfish, etc...)
- Natural food source of tangs and other algae eaters