If this is a newly cycled tank, the hair alage is normal and many snails and crabs will work and are less headache afterwards. They are also easily removed if you end up with too many post algae removal.
Using fish to handle problems can somtimes lead to more problems. If you must have a fish, lawnmower blennies are good for smaller tanks (but they will get several inches eventually) or tangs are good for larger tanks. Stongly advise not adding a tang just to solve an algae problem.
Livestock to control alage is just a band-aid. While test kist may show negative (because the alage is consuming the nutients), nutrients (phosphate and nitrate) are fueling the algae and will continue to do so. Its best to address the issue head on with water changes and/or chemical media such as grannular ferric oxide (GFO) which is commonly sold as Rowaphos and many other names.
Lawnmower blennies are your best bet. Try running GFO to slow the algae down and control natural light hitting the tank if possible would help with this. Lowering lighting cycles will also reduce algae outbreaks.