Green spot is due to good parameters and much lighting. Reduce lighting, will help decrease their growth. No fishs/shrimps eat that, must be manually removed with scrubbing sponge (no steel whool, just the yellow sponge with a green scrub pad)...
If it's glass aquarium you can remove it via sharp razor blade. When I had this problem, I waited that there's spot everywhere, then give a good razor blade shot.
If you have others algae like staghorn, green hair, siemensis algae eater are great, gyrinochellius CAE too... Don't go with pleco, they require 100g+
I had a big algae problem in my 10g, so I have put a small gyrinochellius for 3 month. Once algae problem finished, I gave it, because It would have outgrow my tank fast.