Depending on your water perameters depends on the fish. Easier to get fish suited to the water rather than the water suited to the fish!
A small group of Harlequin Rasboras might work quite well, They stay more towards the top half of the water column, look great and the smallest shoal size you would need is 6.
A small group of Harlequin Rasboras might work quite well, They stay more towards the top half of the water column, look great and the smallest shoal size you would need is 6.