Will this work in my fish tank?

I have a 55 gallon tank with 7 neon tetras, 6 white skirts, and 1 angelfish ( Cupcake :D ) Dont worry, Cupcake is almost adult sized and doesn't mess with any tetras. I wanted to get 4-5 kribensis and 1-2 keyholes. The hardness of the tank is 120 gh and the ph is 6.0. They are plenty of decorations. The kh is 80.