Algae is a good thing...but when you have large outbreaks like you are seeing this is a bad thing. It indicates large amounts of nitrates and phosphates in the water column. Using ro
water for top off and water changes, large water changes to bring those levels down, minimize feedings to ~3 times a week...sparingly of course, and manual removal during water changes.
Algae issues is a long battle that won't be won over night. Keep up with it and you will reap the benefits of your patience and determination.