I strongly suggest not using any chemicals for algae removal. They IMO are not safe when used in tanks and is inhabitants.
What type of algae do you have? Can you post a picture? What type of lighting do you have and how long do you run it daily? What is your nitrate reading? How much water do you change out weekly? Do you have plants and if so do you use any ferts? Algae is present in a tank when lights/CO2/and ferts are out of balance.
For starters only run your lights 6 hours max daily until all algae issues are resolved. Also if you answer the above questions and we can identify what type algae your dealing with many types of algaes can be spot treated using Excel or Hydrogen Peroxide 3%.