12 hours+ is a lot of light. I would cut it down to 8 hours. Get a test for nitrates and see how high your levels are.
18g (Red Cherry Neo Shrimp | Malawa Shrimp)
7.5g (Yellow Neo Shrimp)
3.2g (Pumpkin Neo Shrimp)
11.4g (new home soon for the Pumpkin Neos)