Green and Mustard algaecide Swimtrine plus
This works really well. Make sure you shock, use your algaecide and proper filtration. I recommend a 36 hour treatment. Shock, use algaecide and use a wire brush on the mustard algae. After the first 12 hours of running your filter, shock it again. Shock a 3rd time at 24 hours, 4th at 36. After 36 hours, clean your filter out as best as you can.. another thing I’ll include is controlling your phosphates. Not a lot of people mention about phosphates but if you have surrounding trees/bushes that are getting into your pool, it’ll increase your phosphates, which is food for algae. Let me know if you need anymore help !
Edit: forgot to mention; Hasa Phos out works really well at reducing your phosphates. You should add this once the algae is gone.