To me, that tiny bit of green algae in your tank is a sign of a healthy environment, and makes a tank look more natural.
Algae helps control nitrate, in order to be completely devoid of algae, a tank would need to have a jungle of plants that out compete the algae for nitrates.
Or more frequent water changes would need to be done, not 75% each time, but many more than once per week to reduce nitrate to almost 0ppm.
I doubt your shrimp will last long enough to make a dent.
Cenote Cristallino below, has very light colored rocks where algae is constantly grazed on by mollies, and yet still lots of algae.
How to recognize if my pbass are really stressed???
The photo of them wad during their "sleeping" time and after just adding the powerhead that's why they sat on the bottom otherwise the swim like a lot and eat also good.
They eat like 20 pellets twice a day.
Sent from my LT18i using MonsterAquariaNetwork App