I use Seachem liquid ferts: flourish, excel, pottasium, iron, and phosphate. Dosing a 12g long I do 2.5 ml excel (use to do 3ml but lot of new rock in tank so lass water volume), 0.15-0.2 ml flourish, phosphate and potassium daily, every other day 0.3 ml iron. My cherry shrimp breed like crazy.
I also have a low tech 2g cookie jar with a few shrimp that breed. Tank gets daily 0.4 ml excel and 0.1 ml flourish.